Problem with external VGA

[Miner, Jonathan W (US SSA)]

I've got a Dell Precision M4600 laptop, running Fedora 17.  Sometime after kernel
3.7.9-104, the external VGA output no longer works.

If I boot with 3.7.9-104,with my projector attached, it is recognized.  If I boot with
3.8.4-102, external VGA devices are not recognized.

lspci:
01:00.0 VGA compatible controller: nVidia Corporation GF108 [Quadro 1000M] (rev a1)

(I've tried running the driver from nVidia, but that has screen rendering problems,
with blocks of random data instead of my normal background pic)

- Jon