Problems with EZ Drummer2

I have just installed EZdrummer2 a couple of days ago and i am having terrible trouble with protools now. protools keeps stalling even if i have one stereo instrument track with ez drummer on it. I have been on to toontracks but they said to contact avid. It seems to me that ez drummer is buggy. Even if i increase the hardware buffer to 1024 it can stall. Sometimes it works fine and then it just freezes. I have protools 8.0.5, Osx 10.6.8 imac Intel dual-core 2.66GHz, 2 gig of ram. Protools runs without any problems without ezdrummer. Any help would be gladly appreciated:-)