For anyone with similar problems:
It's the BIOS. I recently updated my Ubuntu installation to Precise and at the same time I thought it was a smart move to check for a BIOS upgrade. Which there was. Upgraded to A22 and the problem started to manifest itself:
When the laptop woke up from suspend, the screen was constantly flickering. At first I suspected Ubuntu, but when I got to a console screen (Ctrl+Alt+F1), the problem was still there.
Downgradig the BIOS to A21 did not solve the problem, but another downgrade to A20 did!
Hope it helps someone.
00:02.0 VGA compatible controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 07)