Cannot output 1080p ingame anymore, only 720p ? (ATI)

[Phat Momma Hoe]

I used to run an ATI 4870x2 on this machine, running 1080p via a DVI->HDMI lead on my screen (Panasonic TX37LZD70). Never had a problem until one of the cores died.
I've an old nVidia 8800GTS that I threw in until I got around to replacing the old card, again, happily playing games at 1080p (Mostly WAR, recently RIFT). However, I received a new 4870x2 a couple of days ago but I'll be damned if I can get it back to playing games at 1080p, will only allow upto 720p !

I've tried both DVI ports on the card
Tried a Belkin Pure AV DVI->HDMI lead
Tried a HDMI lead with a DVI/HDMI converter
Tried a standard VGA lead
Fiddled with every setting in CCC

Its @1080p on the desktop as I write this, yet as soon as I try a game the highest available res is 720p and its driving me absolutely nuts as I cannot figure out why !
I noticed someone else having the same problem with an ATI card, but there was no conclusion to the thread so have no idea if he had fixed it.

I've used driver cleaner pro a couple of times to make sure there is no dodgy driver files left from the 8800, done a clean install of the ATI ones several times with no luck.

I'm assuming its a driver issue of some sort, unless one of you good chaps can help me out before I go back to my old nVidia card again !

 

[Phat Momma Hoe]

Tried everything except various driver sets. Working under the assumption that as using large HDTV's is becoming more common place that it would be something that wouldn't / shouldn't be an issue with the latest driver sets.

Just wish I know what I did differently (if anything at all) with my other 4870x2

 

[Phat Momma Hoe]

Will give another driver set a wizz tomorrow, had enough of it today