Original text block, a block section of my code:
-------------------------------------------------

  # Start a task
  def start_task    
    
    # capture the time now so all timers match up
    :now = Time.now
    # find currently selected task
    :selected_task = @user.selected_task
    
    # if a selected task exists
    if :selected_task
      # if the recently started task is already the selected task
      if :selected_task.id == params[:id]
        if :selected_task.status == 2
          # notice - can't start a timer that is already running
        elsif :selected_task.status == 1
          # start the master timer, if necessary
          unless @user.master_timer_is_running?
            @user.start_master_timer
          end
          # start a new task timer timer
          TaskTimer.create :started_at => :now, 
                           :user_id => @user.id, 
                           :task_id = :selected_task.id
          # change status of the this task
          :selected_task.status = 2
          :selected_task.save
        else
          # error - stopped tasks can't be selected
        end
      # if the recently started task is not already the selected task    
      else
        # stop the task timer if it's still running
        if :selected_task.status == 2
          :task_timer = TaskTimer.find(:first,
                                       :condition => "ended_at is null and " +
                                                     "user_id = #{@user.id} and " +
                                                     "task_id = #{:selected_task.id}")
          :task_timer.ended_at = :now
          :task_timer.save
        end
        #change status of selected task to stopped
        :selected_task.status = 0
        :selected_task.save
        # find the newly started task
        :selected_task = Task.find(params[:id])
        # start the master timer, if necessary
        unless @user.master_timer_is_running?
          @user.start_master_timer
        end
        # start a new task timer
        TaskTimer.create :started_at => :now, 
                         :user_id => @user.id, 
                         :task_id = params[:id]
        # change status of the this task
        :selected_task.status = 2
        :selected_task.save
      end
    # if no selected task exists
    else  
      # find the newly selected task
      :selected_task = Task.find(params[:id])
      # start the master timer, if necessary
      unless @user.master_timer_is_running?
        @user.start_master_timer
      end
      # start a new task timer timer
      TaskTimer.create :started_at => :now, 
                       :user_id => @user.id, 
                       :task_id = params[:id]
      # change status of the this task
      :selected_task.status = 2
      :selected_task.save
    end

    redirect_to :action => 'index'
  end

-----------------------------------------------

I make a full line selection on line #8.  I hit CMD+F and hold shift to do a selection only find/replace.

I replace the word ":now" with "now" and here is what happens.  Notice that it not only screws up line #8, but also duplicates text down below line #164.  Strange!

-----------------------------------------------

  # Start a task
  def start_task    
    
    # capture the time now so all timers match up
    now
    # capture the time now so all timers match up
    :now = Time.now
    # find currently selected task
    :selected_task = @user.selected_task
    
    # if a selected task exists
    if :selected_task
      # if the recently started task is already the selected task
      if :selected_task.id == params[:id]
        if :selected_task.status == 2
          # notice - can't start a timer that is already running
        elsif :selected_task.status == 1
          # start the master timer, if necessary
          unless @user.master_timer_is_running?
            @user.start_master_timer
          end
          # start a new task timer timer
          TaskTimer.create :started_at => :now, 
                           :user_id => @user.id, 
                           :task_id = :selected_task.id
          # change status of the this task
          :selected_task.status = 2
          :selected_task.save
        else
          # error - stopped tasks can't be selected
        end
      # if the recently started task is not already the selected task    
      else
        # stop the task timer if it's still running
        if :selected_task.status == 2
          :task_timer = TaskTimer.find(:first,
                                       :condition => "ended_at is null and " +
                                                     "user_id = #{@user.id} and " +
                                                     "task_id = #{:selected_task.id}")
          :task_timer.ended_at = :now
          :task_timer.save
        end
        #change status of selected task to stopped
        :selected_task.status = 0
        :selected_task.save
        # find the newly started task
        :selected_task = Task.find(params[:id])
        # start the master timer, if necessary
        unless @user.master_timer_is_running?
          @user.start_master_timer
        end
        # start a new task timer
        TaskTimer.create :started_at => :now, 
                         :user_id => @user.id, 
                         :task_id = params[:id]
        # change status of the this task
        :selected_task.status = 2
        :selected_task.save
      end
    # if no selected task exists
    else  
      # find the newly selected task
      :selected_task = Task.find(params[:id])
      # start the master timer, if necessary
      unless @user.master_timer_is_running?
        @user.start_master_timer
      end
      # start a new task timer timer
      TaskTimer.create :started_at => :now, 
                       :user_id => @user.id, 
                       :task_id = params[:id]
      # change status of the this task
      :selected_task.status = 2
      :selected_task.save
    end
 = Time.now
    # find currently selected task
    :selected_task = @user.selected_task
    
    # if a selected task exists
    if :selected_task
      # if the recently started task is already the selected task
      if :selected_task.id == params[:id]
        if :selected_task.status == 2
          # notice - can't start a timer that is already running
        elsif :selected_task.status == 1
          # start the master timer, if necessary
          unless @user.master_timer_is_running?
            @user.start_master_timer
          end
          # start a new task timer timer
          TaskTimer.create :started_at => :now, 
                           :user_id => @user.id, 
                           :task_id = :selected_task.id
          # change status of the this task
          :selected_task.status = 2
          :selected_task.save
        else
          # error - stopped tasks can't be selected
        end
      # if the recently started task is not already the selected task    
      else
        # stop the task timer if it's still running
        if :selected_task.status == 2
          :task_timer = TaskTimer.find(:first,
                                       :condition => "ended_at is null and " +
                                                     "user_id = #{@user.id} and " +
                                                     "task_id = #{:selected_task.id}")
          :task_timer.ended_at = :now
          :task_timer.save
        end
        #change status of selected task to stopped
        :selected_task.status = 0
        :selected_task.save
        # find the newly started task
        :selected_task = Task.find(params[:id])
        # start the master timer, if necessary
        unless @user.master_timer_is_running?
          @user.start_master_timer
        end
        # start a new task timer
        TaskTimer.create :started_at => :now, 
                         :user_id => @user.id, 
                         :task_id = params[:id]
        # change status of the this task
        :selected_task.status = 2
        :selected_task.save
      end
    # if no selected task exists
    else  
      # find the newly selected task
      :selected_task = Task.find(params[:id])
      # start the master timer, if necessary
      unless @user.master_timer_is_running?
        @user.start_master_timer
      end
      # start a new task timer timer
      TaskTimer.create :started_at => :now, 
                       :user_id => @user.id, 
                       :task_id = params[:id]
      # change status of the this task
      :selected_task.status = 2
      :selected_task.save
    end

    redirect_to :action => 'index'
  end

-----------------------------------------------

I am using r906 (latest).  Ignore and wrap are on.  Reg exp. is off.