The requests for PG to implement VST fully have now been ongoing for the past 4-5 years. PG are clearly not interested in improving this feature for customers - so Jamstix, EZDrummer and many other VST's do not function properly - if you want to save many hours of frustration just buy another sequencer.
2010.5 has brought us a Conductor - who on earth needs a conductor in a sequencer?
Just my 2c
Roy