Have you tried the banal trouble-shooting routines (trashing prefs by keeping command-alt-shift/ctrl-alt-shift pressed while starting Photoshop after making sure all customized presets like Actions, Patterns, Brushes etc. have been saved and making a note of the Preferences you’ve changed, 3rd party plug-ins deactivation, system maintenance, cleaning caches, font validation, etc.)?
I actually haven't used Photoshop untill today after the reinstall, so it should be clean, but I can try.
I'm more worried that some settings from the previous install acutually made it work, and now when it's gone,
it will not work.
Edit: Funny thing, if I make the documet stand alone and drag it over to primary screen I can see the content.
I can also see the content when dragging the window around on the secondary screen.
But when I release it, it becomes dark grey, and I can't see any updates I'm making.
Tried both reset and migrate from previous versions. Still same problem.
My computer has 2 graphics cards, GeForce GTX 460(Primary screen & projector) and GeForce 210(Secondary screen).
Photoshop detects my GTX460 and uses it. But when I move Photoshop to my secondary screen I can't see any documents.
It's just a gray screen.
Photoshop does not support 2 graphics cards. Almsost all modern cards will support at least 2 monitors, so 2 cards are not necessary.
Disable the weakest card and think you will do just fine.
Yeah, as you say, they support two, not three!
Pirmary screen + Projector + Secondary screen = 3 devices.
And it has been doing fine until CS 6. I always run PS on my secondary screen,
and GPU rendering has also been doing fine.
So NO, i will not disable one of the video cards.
Edit: They have three connections eg. 2 x DVI + HDMI, but only two works
at the same time. Also HDMI in primary connection independent of your settings.
So if you use HDMI to the PJ and DVI to your screen the PJ will become main device.
Not so good at all for a computer.
There might be a card out there supporting three screens at the same time,
but in that case it's cheaper to by a new cheap Geforce thats supports CS6
and use the same setup. Cause as I said, it's been doing great until the reinstall.
It's been running just fine for the past 2 years with both Photoshop CS5 and Photoshop CS 5.5.
No problems at all. It's something in Photoshop CS 6. Hopefully Nvidia will realease an update with a fix.
Otherwize I have to buy a new secondary graphic card.
But their user forum is down for repair, so I can't ask there.
It may be more luck than design that the setup worked for you. Even the Adobe engineers have posted that Photoshop does not support 2 graphics cards. And like Noel said with 2 different cards you are really stretching your luck.
CS6 puts a lot more stain on a GPU so that may be one reason why you are having more problems.
Computer hardware and software are great, but at some point you are best served to accept Reality rather than rely on Hope.