Previously I thought the issue was the windowTitle variable in .tm_properties. I was wrong... again.
the title bar anomaly is caused by this:
excludeInFileChooser= "{$exclude,*.xib}"
In fact, simply using the variable, excludeInFileChooser, appears to corrupt the titlebar:
excludeInFileChooser= "{*.xib}"
Those lines are from here: http://wiki.macromates.com/Reference/FolderSpecificSettings
HTH!