jittering/flickerin screen on my SL500, but only after sleep

[yup]

Hi,
my SL500 is jittering. I seems to happen only after the computer has gone once into sleep mode (though I am not certain about that. It looks similar to shat happens when you put a cellphone next to a CRT screen. I is usually horizontal lines, but I think vertical happens too. I seems to get worse with time, till the restart.

I think it started when I installed win7

I put all the drivers I though I needed from lenovo's site, but my assumption is that it is a driver problem as the computer is in tip top condition and as I mentioned it seems to only happen after sleep.

note that I tried formatting an starting from the begging, but the problem came back

thanks