Comment 17 for bug 158855

After some digging I found this:
http://dev.compiz-fusion.narkive.com/BXRBj9Xp/fusiondev-bug-545-escape-used-as-part-of-any-key-binding-has-no-effect

Where it suggests that this is by design.

This doesn't satisfy me. Reserving a lone escape is fine, but preventing Esc with modifier keys seems crazy. I'll keep looking for other code about it.
This "bug" has been around for the life of compiz and now through a C++ "rewrite" :-)

Also reported here: http://forums.linuxmint.com/viewtopic.php?f=47&t=24397

I'll probably open a new bug since this has been closed. OTOH, only 10 people reported that it affected them.
It'd be nice if it got more love.