Well, this is quite the odd dilemma I seem to have....hopefully someone can help.

In short, I leave my 'box' on pretty much 24/7....well, that is until one of the following occurs:

I wake up/come home, turn my monitor on and 1) it has reset itself to the login screen, 2) appears to be in sleep mode and won't 'wake up', 3) is completely off.

Bare in mind, when I leave the computer, I leave it on, with whatever 'windows'/programs open I was working on, and come back to said items when I get back. 9/10 times, there is no problem. I come back, everything appears hunky dory. However, that 1/10 times seems to be on the rise, and annoys/bothers me, as I don't know how it could be happening.

It's on a new harddrive, there's nothing wrong with it, as I've checked....

Oh, and before anyone asks, Mandrake 10.

So, hopefully someone will be able to shed some light...if you need some more info, feel free to ask...if you have a solution, even better.

have you tried "going out", then sneaking a peek at your monitor through the window for a couple of hours?

Sorry, no real help I know, but if it's any consolation I've seen Windows boxes do that too.

I had exactly this symptom some time ago. It turned out to be a faulty power supply, which was not handling transient mains spikes properly. Found out by fitting a mains logger borrowed from a freind of mine. Not saying that is your problem, but worth a look at the voltages coming out of your psu.