Trying to trouble shoot HTPC problem (1 Viewer)

[Topher5000]

MediaPortal Version: 1.1.0 Beta 1
MediaPortal Skin: Revision/Xface
Windows Version: Windows XP (SP3)
CPU Type: AMD X2 3800
HDD: WD 500gb + Seagate 1tb
Memory: 895mb
Motherboard: MS-7207PV (MSI) K8NGM2
Video Card: Asus EN8600GT Silent
Video Card Driver: PureVideo 1.02.223
Sound Card: Realtek High Definition Audio
Sound Card AC3: coaxial out
TV: Epson HC720
TV - HTPC Connection: HDMI

In the last couple of days my HTPC has been just shutting off. It'll just go dead. I have to flip the switch on the PSU, unplug the cord, plug it back in & flip the switch.
My first thought was the PSU, so I've tried 4 different ones & it still happened. I then tried new RAM, but it still did it.
What's odd is that it only happens after I start MediaPortal. I'll boot up, start MP, try browsing the movies & it'll shut off. I've booted up, started Media Player Classic & played a 16gb HD .ts file for an hour and a half with no problem. During this, the system temp rose from 28c to 31c & the CPU temp went stayed at 35c. These are from the BIOS.
I then started MediaPortal & it shut off while browsing the movies.
Is it even possible that a software problem would cause this behavior?

 

[wowski]

Maybe check the Powerscheduler settings for Mediaportal and TV server, they could cause the PC to shutdown after a set amount of time. Not sure about the need to unplug though, that sounds a bit more like a hardware issue?

 

[Topher5000]

That's what I was thinking, but I can use Meedios (yeah, try using that without a LOT of reading) & XBMC with no problem. Anything to do with MediaPortal crashes it though.
I restored the computer to a month back, unistalled MP (the full uninstall) & tried reinstalling it, but it still crashes.
I'll try reformatting the HD & starting from scratch before I think about a new mobo & CPU. It doesn't cost anything & I'm off next week so I'll have the time. In the meantime I can still play music using the Xbox upstairs & watch movies with Media Player Classic.