Fedora Shell won't display with two connected monitors
I installed Fedora 17 64-bit to my computer while only using one of my monitors, but recently I re-installed the second one which seems be interfering with the displaying of the shell. When I boot into Fedora the monitors flash briefly before they stop receiving a signal. None of the Fedora loading output is displayed, and after sleeping for almost 6 minutes, the monitors will receive a signal again at the Gnome login screen. In addition, when I try switching between terminals (Ctrl alt F2 etc), the shell login doesn't display. However, I know I am in fact in the new shell because if I login blind and start Gnome, it displays a desktop after a minute. Also, in the week or so after installing Fedora during which I was still using one monitor, I had neither problem. Furthermore, if I unplug one monitor before booting, the boot proceeds normally, but I don't fancy the idea of unplugging a monitor every time I want to boot fedora.
It's also worth noting that the problem has extended the time for the system to boot from the 25 seconds it usually takes from the start of the fedora boot to the gnome login screen to about 5.75 minutes. I have a P8Z68-V Pro motherboard, GTX 560ti graphics card and its connected to both 23in and 20in Acer monitors via DVI. I'd appreciate any help or suggestions; thanks.