Audio dropouts from soft synths?

I am having some problems that I can not seem to get away from. I am running XP (current on all updates) and followed the directions for settings from XPaudio (or something like that) web site. The problem is that when I run Sonar 4 (which is also updated to current) and open up a VST like Kontakt and start to play the audio seems to pause for a moment (breif silence) and then it pumps in all the notes I played all at onec and then starts working right for a few seconds to a minute or so and then repeats. My demo version of Pro53 from NI works with no problems at all. Battery works Guitarrig, Amplitude, BFD, and a host of others work right but a few do not.

Problem #2
I am using Sir108 for impulse reverb and when I tried to update it to the newest version (copy and paste to VST folder and run VST adapter so it would be seen.... the system goes BSOF (blue screen of death).

Any ideas on either of these problems?