Ubuntu has applied some patches to Qt that are binary incompatible with Squish binary packages provided by froglogic.
You only need the libraries. You can install them into a new directory in your user account, and then re-run Squish
setup and point to the newly installed libraries in that directory.
Verified with: Ubuntu 10.04 and Qt 4.6, Ubuntu 10.10 and Qt 4.7 (64-bit)