one thing I ran into is trying to get the citrix client working (yes, a binary-only app), it needs various other libraries, including X libraries. these are not part of the stuff supported by the 32 bit compatibility libraries.
I don't run many 32 bit apps, but I've run across a half dozen of them that have required that I manually download and install some 32 bit versions of packages on my 64 bit machine before they work.
however, I have been able to get every one of them to work.