Card won't boot with DVI-HDMI adapter

[Forceman]

I've got two older Nvidia cards (8600GT and 8800GT) I am trying to use in an HTPC, but when I have either of them hooked up to my TV via a DVI-HDMI cable, the system won't boot (it goes to a blank screen after the boot screen, but Windows never loads). I can boot it with the cable unplugged and then plug the cable back in once it's booted and it runs fine, but that really isn't a long term solution.

Anyone know of a fix/workaround for this problem?