7600 GT installation does not work

Hey guys,
I need your help for setting up an SLI-configuration!

I've got two Nvidia 7600 GT, with same amount of memory, but from different manufacturers and with different clockspeeds, but that shouldn't be a problem. Both cards are working when in single configuration by the way. When I tried to install them I was doing exactly what the how-to at slizone.com shows.
First installed one card in PCIe-slot, booted and installed the driver. Then shut it down and installed the second card with the SLI-bridge.
So, again, power on and boot. Then I "should" get this message: SLI-bubble-message

I didn't get it on the first boot, so I shut down and booted again, and then I got the message, clicked on it as described to turn on SLI, but it didn't work obviously, as there is no option for it in the driver's settings.

GPU-Z shows that SLI is available but disabled on the tab of the first VGA, for the second it just shows disabled.

So who can help me to get SLI to work properly? :confused:

Something quick and easy and the first thing I would do, Is flash both cards with THE SAME BIOS. Choose a bios with stock clocks for core and ram (you can always OC them later) then I'll bet my 1 year salary that all will be ok. I know........Different manufactures, different clock speeds etc shouldn't matter, but I found for some reason that the BIOS'es love to be the SAME for both cards.... Try it, cant hurt. Remember, to be safe, flash 1 card at a time, and to be even safer, only have 1 card in the PC as you flash.