You could open up an xterm, and type 'whereis gcal'
it could be somewhere that isn't in your path, although that seems unlikely. You can also run 'whereis calctool' just to be sure that's there as well. I'd say try running them from a term, just to be sure they don't work, plus that way it might output something to STDERR, which will give you more info
I assume you're compiling from source after reading your other posts. Have you bothered trying the rpms?