Problems when plug-in interfaces are visible in Pro Tools

[bms9nmh]

Hi Guys,

I've recently bulit a new computer which was a serious increase in power from my old computer. After installing Pro Tools and a few RTAS plugins, the performance is being affected everytime an RTAS plugins interface is visible within my pro Tools session. The tune i'm currently making seems to run fine when i insert FX, but with several of these plugins, when i maximize them and view there panels/interfaces pro tools starts chuggin and popping and i occasiobnally get messages telling me to increase/decrease H/W Buffer size which never seems to work. When I view "System Usage" within Pro Tools, The CPU (RTAS) is fairly low during the tunes playback (about 1/15 of the maximum), but becomes fairly erratic when certain plugins are clicked and visible. Does anyone know what this could be???

Here my hardware:

Intel Q9650 3GB Quadcore Processor
ASUS P5Q Deluxe Motherboard
OCZ 4GB 1200MHz RAM
Mbox 2 Pro
Asus EN210 GeForce210 Graphics Card

I'd really appreciate any help,

Thanks Guys

Neil