I just upgraded to Parallels 5 from 4. I am running build 9220 on a 13" Aluminum Macbook and Mac OS 10.6.1 Snow Leopard. The guest OS is Windows Vista. I am running an application called SeeYou version 3.92. In the 3D animation mode there are text characters that overlay the animation, these characters are refreshed every frame or so. Under Parallels 4 the characters would be updated, but under Parallels 5 they are overwritten so that within a couple of seconds the text turns into a solid black blob as text piles on top of itself rather than the characters from the prior frame being cleared first and replaced with the new text.