I installed Citrix on a Ubuntu 11.10 (x86), more or less the default configuration. Everything seems to be fine but:
Dropdowns don't behave nice, when clicking a drop down, I have problems to select items. Sometimes I click on the right item but the wrong item gets select. In fact it's pain to use the mouse, using keyboard everything is much easier.
What could be the problem? Compositing window manager? Motif?
I followed the installation guide I posted here: Citrix client installation and configuration in ubuntu 11.10 or 12.04
Update: problem still exists with Ubuntu 12.10. There are focus issues which can be solved with Windows maximizing/undoing maximizing. The problem is particularly severe in the Ubuntu default config, XFCE makes it less severe. About the installation, there is now an official Ubuntu guide: http://wiki.ubuntuusers.de/Citrix_ICA_Client
BTW: I can assure that it's a Ubuntu problem, on Windows it's a non-issue.