GTX 570, three monitors asking to move

[Vatharian]

Hi!
Finally, I've thrown out my two old 17" 1280x1024 LCDs and got three monitors, all bought at the same time (DELL U2412M - they should differ in nothing but s/n), and happily connected them to my two GTX570 in SLI (both same model from EVGA, same BIOS). I've tried to setup surround, but the nVidia panel is constantly asking me to move one of the monitors.
From Surround configurator I learned, that middle monitor (no 2) should be on the upper card, while 1 and 3 on the second. If I do this, it's asking me to switch 1 and 3, and when I do, it asks me to do so again - all of this regardless, which monitors I connect where (hell, they're exactly the same, if it finally works, I can move them around).
If I connect any two monitors to the upper card, while all three work independently, when I try to switch to surround it tells me, there are only two monitors - one on the upper, one the lower card. So, I thought that maybe, just maybe, DVI or some switching circuit is broken on my upper card. So I drained my loop, switched cards (which I'm positive I've done correctly, since I marked the cards with permanent marker), only to discover it's doing the same thing.
http://telewizor.eu/forum/viewforum.php?f=9
Is there anything I can do?
At this point I'm even considering GPU change - I can shell out 800 bucks on newer nVidia GPU, but I'd like to have it considerably faster than my current setup, and with that cash I can do probably 4GB 770 (but no waterblock), which would end up exactly the same.

[csimon]

Have you tried any other connection besides DVI?

[Vatharian]

GTX 570 have only two DVI-I, and a mini-HDMI, while U2412M have DSUB, DVI-D and Displayport. This only leaves me with DVI or VGA. Will try VGA in a moment (I have to hunt down DVI-VGA adapters). Will edit.

EDIT: Half success! If I set the resolution to 1024x768, on VGA it works, albeit for one or two minutes, then it simply goes black, finds new monitors and sets them to 1680x1050 independently.

I'm wondering if the fact, that these are 1920x1200, not 1920x1080 plays the role?
Anyone had had success with 2x 1200 monitors?
http://telewizor.eu/hdtv.html
EDIT 2: After more fiddling, with custom resolution 1024x640 (proper 16:10) I can haz Surround on three monitors, using VGA adapters, without monitors disconnecting.

The cables I'm using came from Dell with LCDs, and since I use ton of them at work, I know they're pretty solid. Swapping DVI cables is stupid.
But, seriously, WTF? Any ideas?