Comment 9 for bug 990129

I had the same problem after upgrading my Dell Studio laptop from 11.10 to 12.04. The system would not wake after suspending. Instead I got a black screen and had to switch the machine off and on. Whilst trying to fix another upgrade issue (loss of wobbly windows) I downloaded and activated the Nvidia display driver and rebooted the machine. Then suspend and resume worked as expected (and wobbly windows!).

I don't know why the Nvidia driver was deactivated/lost during the upgrade. Another machine I use also upgraded from 11.10 to 12.04 without deactivating its Nvidia driver.