No signal to monitor

[GiganticDays]

Setup:-
Epox EP-9NPAJ-SLI motherboard
AMD X2 64-4200 CPU
Gigabyte HD3450 Graphics Card (ATI)
4Gb RAM
Windows Vista Ultimate 32-Bit

I'm currently using the above as a media PC hooked up to an Albatron LWX-30AMS 30" LCD monitor/TV via DVI.

I often access it via remote desktop from a laptop running Vista Home Premium. Problem is, after closing a RDC session and trying to use the media PC directly, the monitor shows "no signal" from the video card. The PC is running as I can still access it remotely, it's just not putting out a video signal to the Albatron. Rebooting solves the problem but that's not convenient.
This doesn't always happen but more often than not. The same symptom can sometimes present if I boot up the PC before turning on the Albatron so perhaps there's a clue there.
I Googled this problem and found a blog which offered some potential solutions (turning off smart-card support in RDC, logging off the RDC rather than just closing the connection), but they didn't work.

I've also tried setting up a hotkey combination to start ATI Catalyst Control Center and have set CCC to force detection of the monitor when it starts up. That worked once but didn't work the last two times I tried.

Any ideas out there?

[GiganticDays]

I've established, by trial and error, that this is not Remote Desktop-related. It only happens when I turn off the monitor.
When I turn it back on there's no signal.
The machine is primarily used as a media server and sometime HTPC so it's not convenient or economical to have the monitor switched on all the time.

I have the latest ATI drivers installed.