Problem with SONAR 2.0 XL

So yeah I'm still using 2.0. Never had a need to upgrade really. Dell Laptop XP Home P4 2.4Ghz Tascam US-428 interface. Anyway, I recently went from sp1 to sp2 and I'm having problems with recording and playback. Major stuttering and skipping. The thing is, when I play back tracks that were recorded before I had sp2, no problems at all!!! This is only happening when I try to record/playback something new. Another problem I see is that when recording 4 tracks simultaneously, 2 of the tracks record a bit behind the other 2. I know I can always nudge but I've never had this problem before. The only other thing I can pinpoint that has change is that I installed iTunes.

Any ideas on what the problem is and how to fix it?

doing that now...any ideas on what the problem could be though? 2.0 has been fine for me these past 4 yrs...

thankyou both for the responses. well, i updated to 2.2. nothing. i then, just for the heck of it, switched the driver mode from WDM to MME. That worked but I then lost 2 I/O's on my us-428 interface! So I had to switch back. I'll mess with the latency next.