Sound Playback Problem + A Plugin File Question

Hi there ,
I just upgraded from MC6T to Sonar x3 , For the most part MC6 has been very stable. Sonar X3 seems stable but here n there il get a few similar problems with playing sound.
 
excuse the waffle ! just trying to explain the issue ...
 
First off, Loaded a plugin ( new download ) Pressed a key in piano roll played note then glitched to a high freq hiss , remove plugin sound stopped ,, so deleted this from comp , 2nd time this happen was with crystal synth that i have been using in MC6 without any issues exact same problem.
Ok now same kinda problem........
This was during playback of track , more like a CD getting stuck but with lots of hiss and glitching, even when i stopped playback it continued forcing me to shutdown Sonar X3 to stop sound from playing, this wasn't caused by adding anything new to track , i pretty much just fired up Sonar X3 and had a listen to see how it sounded, it was when i decided to turn off a delay after a few play backs the sound locked in to jump mode ... must add.. iv put alot of work in to this track so far and it has never crashed sonar up till this point..
 
any ideas whats going on ? any settings i need to change ?
 
Win 7 32bit , 4gb ram
 
Finally...
Sorting out my VST plugin's (what a mess), If i was to Sort out my plugs by type moving them in to different folders , Will sonar detect new file location of plugs for previous saves file's ?
 
thanks....