Hi Jean,

>In fact, it was a bad soldering contact onto the mainboard. While cold, the PC
>worked fine. But when hot, after a few hours, due to dilatation, the solder >did not get
>in contact and the PC hanged up sometimes. Sometimes because it appeared only >if
>the monitor was placed onto the CPU case causing box deformation ...

mmmm ... interesting... however, I had also changed the motherboard of
this unit just before changing the hard disk.

Just recently I've noticed that it was using CHS(?) instead of LBA
in the CMOS configuration. Do you think this could be the problem?

>Excuse me for the delay but I was on holidays.

No problem... Hope you had a good holiday. :)