I had some trouble getting the ICA client to connect to a site in Ubuntu today. Actually, it’s been for a few days. I’m not entirely sure if I’ve used Ubuntu for Citrix stuff.
Anyway, whenever clicking on a connection on the Citrix web interface, the webica application would fail with this error: “Proxy connection failed: [...]

Installing Citrix correctly, and with confidence is generally an important issue. Some bad choices early can cause you a lot of headaches later on.
Today, I found a good site a Methodology in a Box, which outlines good practices for deploying various versions of Citrix and TS.
Even better, the guides can be downloaded in PDF format!