Parallels 4 incredibly slow!

I recently upgraded my Macbook Pro to Snow Leopard, and as a result was forced to upgrade my version of Parallels to 4.0.

The upgrade went OK. However, the new version of Parallels is running MUCH slower than the old version. It also sometimes refuses to wake up from being suspended. Also, after waking up from being suspended it's even slower than if never suspended at all.

I've already tried the following knowledgebases:

http://kb.parallels.com/en/5778
http://kb.parallels.com/en/5859

Please help!

thanks