Solaris: Blade 150 - XWINDOWS Problem

Hi,
I have a Solaris 8.0 BLADE 150 machine. I have an onboard graphics alongwith an addon XVR500 graphics card. Now, when I use the motherboard graphics, I am not able to login to the XWINDOWS terminal, instead it stays on the console.

But, if I insert the monitor cable to the XVR500 port, then nothing can be seen on the screen. How do I troubleshoot this ?

have you installed the solaris 8 drivers for the XVR500?

it's not nativley supported (at least not in the earlier versions of 8)

there should be a CD included

Yes drivers are installed.