problems with poserfusion

I have poserfusion for 3ds max 9 and I have a bit of a problem. After I have set up my scene in max I will import the poser model. It comes in fine and positions great etc… However I have found that if I continue to edit the scene, move objects, add objects or anything in general, my poser figure will completely vanish from all the viewports. It is still active if you select it, because you see the object box around it, but it just vanishes. The big problem is that when it does this, the poser character will no longer animate when you render it out. It will be stuck on the first frame it is imported as. However if i can manage to bring it into the scene and render it out when it does not vanish, it will animate fine.

This makes no difference when I have the options set to full tracking and loop animation. So what is wrong and why will it randomley vanish causing it to no longer animate when its invisible?