aye definately sounds like you've overheated your GPU at some point
ive done the same thing when the fan died on my old one
but mine wasn't as bad as that
it wont get better, and should be replaced, unless you like playing games, GFX cards are available from about ?20 (about 25 euro's)
that actually brings me to a point, ae they gonna change one of the symbol keys to have a euro symbol, we have pound and dollar, maybe the * of the 8 key could be it