I have a Mitsubishi H3000 front projector connected with a DVI to hdmi cable. I also have a component cable hooked up for menu access and have my xbox 360 on it. I turn off the projector when I am not using it and leave the computer on.
Later, when I turn on the projector I get a no signal from the dvi/hdmi. I switch back and forth on the 990 inputs to see if it jogs something, then I try switching the inputs on the projector and get the same no signal. The onscreen menu works fine and the xbox 360 will display, but nothing from the computer (DVI). If I hit reset on the computer the bios screen pops up and everything is fine until I turn off the projector. Obviously hard stops are bad on the OS (Vista 32). If I hook up an external monitor it works fine as well.
Anyone have any ideas? Because the signal seems to be there when I hook up a regular monitor, I don't think it is the computer.
Thanks,
Nathan

I believe I have a similar problem. My Plasma TV will not detect a signal from my HTPC unless I have it selected to that input when my computer first boots. If the computer boots without the TV on, I get the no-signal behavior when I later go back to that lineup.

In my case I have Linux so I don't need to reboot ;-) I just log on remotely or restart my video server.

If in your case you are also getting this after successfully booting with video, it could be that you have your PC BIOS setup to turn off the video after some time of inactivity.

If your PC has a hot-key or function key combination that switches the video mode, try that the next time instead of rebooting.

Thanks, I will try that....