Gemini,
Sorry for your problems. The only two things I did was one to remove the Vienna Instruments and make sure I loaded them last if I wanted to use Play. Also, and I had a similar problem to you, I would get a similar error that the product could not be found. I would ignore it and even though the screen was white I would save the metaframe. Then close and reopen VE Pro. Play would then load normally.
Here's a picture of one of my instances fully loaded with different Play instruments. All this on a Win7 64 mahcine built on an X58 chipset motherboard and using a Core I7 920.
Don't know if you can see but on the very right of the picture, I overlayed the VE Pro Server to show it was running on 64 bit.