MacBook :: Mini Display Port - Vga Only Works With Lid Closed Then Computer Goes To Sleep?

I have a 2009 unibody macbook pro. I have 42 in lcd tv. I have a minidisplay to vga adapter and a vga cable. When I try to connect the monitor to the mbp when the lid is open nothing is detected. I do not get any options to change to mirror mode or am able to change any settings regarding the monitor. I can change the resolution of the built in display only. Now for the twist. If I connect everything, do a restart and close the lid, as the computer boots up the external monitor works. Its the grey boot screen with the apple logo. But as soon as the computer begins to load the desktop, the monitor losses the signal. At first I thought it was going into sleep mode, so I hooked up a usb mouse to keep the computer awake. I tried the process again, and as soon as it goes to the desktop it losses the signal. So I don't think it is sleep mode.  I downloaded the minidisplay prot firmware update, but because the screen is not detected when the lid is open I cant run it. When the lid is closed the computer either goes to sleep or doesn't send the desktop signal and I still cant run it. Nothing happens if I change between the video cards (9400 and 9600gm). Is it a resolution issue? Do the vga cables have a max resolution that is lower than 1900 x 1200? 

2009 unibody intel macbook pro
running 10.6.8
3.06 ghz 8gb ram