2 Video card set up

[Grzesio]

Hi  can somebody pls. help .
I trying set up 2video card to run fsx in 4 monitors ,my primary video card BFG geforce9800 GTX+ Oc.512Mb.  i conected to Matrox triple head 2go digital going to two 22" wide scren monitors  runed as dual head,till this time  every things going ok. When i conected one or two monitor (19"-4x3,17"-4x3) to my second video card Geforce 9600Gt-Oc-512mb.  to used as ATC, or GPS, or radio panel. monitors are black ,or every thing freez up. What i am doing vrong, can't fsx be played on two diferent video card? Ihave newest video driver,trying used older drive ,doing same things.
My computer spec:
M.b-Gigabyte EP45-UD3P
Procesor Quad core 8200 Oc. to 3Gh
Ram-4 Gb
HD- Wd raptor150GB
Power sup.600W
2-Video card - BFG9800GTX+512mbOC,BFG9600GT 512mb,OC
Vista ultimate 32
FSX Acceleration pack