Computers that are running Windows XP Service Pack 2 and that are equipped with multiple processors that support processor power management features may experience decreased performance
I have an Athlon 64 X2 4400+. I'm not using it a lot yet, and I have no comparsion basis to know if it is being required a lot or not, but I have the impression that my Sonar 5 is not dealing so well with it (the CPU bar fills a lot more than the bars in task manager).
MFC applications leak GDI objects on computers that are running Windows XP
This one I saw at Sonar support page. Never heard about it before.