Are you still using Trillian now? If not, is there a new king-of-the-hill IM client I'm missing out on?
I don't use Outlook (at home) so the Set programm access thing worled fine for me with SP1 and continued to work after updating to SP2.
The only thing I've had to do to SP2 is to open up some ports in the firewall and run a patch to some TCP library that limits the maximum number of connections that can be made at any one time (SP2 lowered this to 10 and I increased it to 50 - previously it had no limit).
Bruno