No X display via HDMI with nvidia driver 256
I have a arch linux based htpc and everything was running perfectly with the previous driver, 195.36. I recently updated to nvidia driver version 256.35 and when I rebooted I no longer have a x display on my tv a samsung dlp.
I am able to see the post messages and the boot messages and even the fallback console, but when I startx, the display goes away. If I connect via the dsub vga, X displays fine. So it seems that only the hdmi is the problem. However, the display is much better via hdmi.
I have review the xorg logs etc but I don't see any issues there. It reports it recognizes my onboard nvidia 9300 and even reports the tv as a samsung (via hdmi). I am using the most basic xorg.conf auto generated during the install. As an additional test, I installed the open source nouveau driver, this works fine with the hdmi so the hardware is fine. I can't really use this though as I need the nvidia vdpau decoding.
How should I proceed?