[TxMt] strange ui,rb error

[Piero D'Ancona]

Help needed. Since a couple days, all my ruby
macros calling TextMate::UI.menu(  )
produce the following error:

sh: : command not found
/Applications/TextMate.app/Contents/SharedSupport/Support/lib/ui.rb:182:in 
    `load': Cannot parse a NULL or zero-length data (OSX::PropertyListError)
	from /Applications/TextMate.app/Contents/SharedSupport
     /Support/lib/ui.rb:182:in `menu'
	from /Applications/TextMate.app/Contents/SharedSupport
     /Support/lib/ui.rb:177:in `popen'
	from /Applications/TextMate.app/Contents/SharedSupport
     /Support/lib/ui.rb:177:in `menu'
	from /tmp/temp_textmate.wMVbb2:17

I am not able to read inside  Support/lib/osx/plist.bundle
since this is a binary file. Can't remember any big changes
in my setup (I moved to Snow Lep a few weeks ago, but
I seem to recall menus worked fine before Xmas).
Any idea or pointers? is Xmas to blame?

Thank you (and best wishes to everyone)
Piero