Thought I'd toss my hat in as well. I'm using a GeForce 5600 Go and have a similar issue, though the details vary a bit. I don't get an nvidia logo or mouse cursor, just the frozen blank screen. I've found a very bizarre work-around in my case. It's a dual boot, and if I boot first to Windows and then do a soft reboot into RedHat, it works just fine.
Here's the link to my thread for anyone who hasn't already read it:
You bring up an excellent point though. Is anyone from NVidia reading this? Is there a more formal process for submitting a bug?