@iMacMiga
Agreed, the towere itself can be most important. Check out
this thread to read through some of the trouble (seemingly random) I was having, only to realise that the tower was ever-so-slightly out of shape, causing the motherboard to bend, and resulting in weird errors.
@OP - from this experience, I would definitely check that your tower is not bent out of shape (look along each edge to make sure the tower is square).
Good luck, I hope you manage to solve your problems.
