f16 nvidia-graphics304.64 problem

I saw new packages for nvidia-graphics 304.51-149 and 304.64-150 for 
kernel 3.6.10-2, which is in Fedora-testing, and gave them a try.  I had 
304.51 running under 3.6.2-1, but had a file conflict and had to remove 
it to install 304.64

On rebooting there was a quick report of a calibration failure, and no 
graphics under either of the kernels.  I had to remove 304,64 and 
reinstall 304.51 from the command line to get back to a usable system.

Device is still GeForce 7500 LE

John P