Crackling noise in Guitar Rig 4.2...does it ever go on sale ??

I'm trying to like Guitar Rig 4.2 but when I use it I'm getting a very obnoxious crackling noise when the program is open. For some reason it seems to corrupt my basic tracks when open. Once corrupted I have to restart Sonar to get the crackling to go away, then it comes back when I try to re-use GR4.2.  Is this corrected when you upgrade to GR5 Pro ?? Is it something in GR4.2 or is it a conflict with X1 ?? Is there a setting that needs to be adjusted ?? Or is it something goofy with my computer ?? I'm really liking some of the preset sounds of the program but the crackling noise is driving me crazy...
 
Does GR5 ever go on sale ??

Yeah I was going to suggest raising your buffer. Amp sims are pretty much the most demanding plugins. Turning off the high quality button on GR (If it was already on) may help. If you want to track with GR at a low buffer (low latency) then you might try bypassing other plugins in the mix to reduce CPU usage.