Re: No hdmi video on Asus AT3N7A-I with versions newer than 195.36.31
I have the same motherboard, and have recently tried to get it finally set up.
So I can say without a doubt that it does (mostly) work with the 260.19.29 driver. The thing that is breaking it for me is the fact that with the 260 driver, it no longer provides the option for the ION chipset to do overscan compensation.
Since the ION is almost specifically tailored to HTPCs and connecting to HDTVs, I can't imagine why this is disabled in newer drivers. From other forum postings, it apparently works fine to do overscan compensation in Windows, but in Linux the option is simply not there.
Could you verify for me that the option is there under the 195.x drivers? If so, I'll try to manage a way to downgrade them for Arch Linux.
For your issue, I can't recall if Ubuntu 10.04 still has an xorg.conf, or if it uses the xorg.conf.d structure, but I would try to rename your xorg.conf (or move the files out of xorg.conf.d) and let Xorg autodetect with only the HDMI cable plugged in and see if it works.