Here is what the revision changes are for 3.59 (pulled from the readme):
History:
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A3.59 -
1. Add some customized settings.
2. Add channel status information of SPDIF output for ATi chipset(SB150/SB200/SB250).
Not sure what the version driver everyone received with the 8790, but my driver on the GX7 was the 3.45. So I had made the move to 3.58 a day or so ago and just saw your post for the 3.59. Made the update.
One issue I have, and the reason I went looking for the drivers, is if I was into a movie or in a game for awhile, my sound would go completely out. To restore it, all I had to do was either exit the game or the movie program (WinDVD) and everything worked fine.
Hoping this resolved the problem. Hard thing is recreating it.

Will see. In any case, I wanted to post the changes from the readme. You can extract the files (without running the program) to get access to the readme.
Thanks.