The GTX 570 is not on the list of cards that Premiere Pro CS5 will use for CUDA processing.
That card is on the list of cards that Premiere Pro CS5.5 will use for CUDA processing.
See this page for a list of cards added for CS5.5.
Navigate to C:\Program Files\Adobe\Adobe Premiere Pro CS5 and open cuda_supported_cards.txt with Notepad.
Add a line with: GeForce GTX 570 and save the file. Then open PR.
Thanks Todd! I misunderstood that part of the memo. I thought all addition included CS5 and wasnot exclusive to CS5.5.
I tried Premiere Pro CS5.5 and the card did work with the MPE. Thanks!