[TxMt] Ruby "Run" command suddenly broken?

[Paul Starr]

In Ruby mode, I'd been using cmd-R to run my trivial little scripts,  
but recently I came back to them and cmd-R no longer works.  It  
simply pops up an HTML window that displays the shell error message,  
'/usr/local/bin/ruby: no such file or directory.'  Running scripts  
directly from Terminal still works, and my Ruby is in fact in /usr/ 
local/bin, so I'm basically stumped.  What did I unwittingly change?

Thanks,

--p.