in trying to fix my stability/graphics card issues, I've run memtest a few times for long periods with no errors. Last night I ran it for 4 hrs with no errors, rebooted to let my gf use the comp and went downstairs to make a cup of tea. I'd forgotten to change the boot settings so memtest started up again and when I came back up (5 mins according to memtest) I found 7 errors on screen and a guilty looking gf. Does that mean I've finally found the errors I was expecting to see (and hence the root of my troubles?) or that my gf was lying when she said she didn't touch it? 
