EDID error on fedora 17

[masoud javadieh]

I want to set non-plugable multiseat under fedora 17. i get the error
" no valid EDID" on one of the two monitors. I get this Error on LG
and SAMSUNG LCD monitors. Changing NVIIDA graphic card to ATI Radeon
was of mo use. the other card is INTEL on board.
Using kmod-Nvidia instead of NOUVEAU could neither solve the problem.
After complete boot one of the  monitor get dead though not completely black.
Any suggestion?