Shoutbox

I've seen some weird things today at my uncle's computer.

His pc has 250mb ram memory, but he always uses more, so he bought a new 512mb one, of the same type, something with 3200 C3 ...
No combination with both worked... actually, if i just replace the original within the new, the computer reboots at the point the desktop should be loaded... if i replace the original one then back again, he works perfectly again. What the .... is going on? (.... = 3 possibilities)

Second:
His computer is connected to the powernet without ground, so there is constantly static electricy on his computer. However he has connected a ground cable with his heatning, which is grounded, and that should work. When I brush that cable to the side of the computer it's one and all blue electric fire (don't know how to call that). His flatscreen is also connected to a powercable with ground, the ground also doesn't work. If I grab the screenconnector that needs to be plugged in into the computer, i also get a shock. This isn't normal right I told him to ground his net and i am wondered that his computer still works that way. Anyway it hasn't got nothing to do with the new memory because i unplugged it completely...