Strange things happen during installation

Greetings!

I’m having a very strange problem. When installing something, a sub-component sometimes goes to 99% CPU and freezes the uninstaller, but as soon as it’s terminated, installation continues without any problem.
I’m using a fully up-to-date XP PRO SP2 32-bit version 2002. I’m running CFP 3, CMF 2, TeaTimer 1.5, Avira 7 and Sandboxie 1.2.

Any idea of what’s going on?

Cheers,
Ragwing