Parallels 7 - Kubuntu 11.10 - Black Screen after Parallels Tools install

On a clean install of Kubuntu 11.10, 32-bit, with all defaults, Installs and boots fine. Parallels Tools also install without errors.

After installing Parallels Tools, kdm starts properly, and I can enter a username and password. However, as soon as i authenticate, the screen goes black and I can do nothing. I can switch to a text console, but switching back to xorg gives be a black screen again.

This is a completely default installation, no customization other than keyboard layout and timezone.

 

This work-around works for me:

1. Press fn+ctrl+alt+F1 to get to a command prompt. I had to click the Parallels window for this to work (Parallels captures keyboard/mouse).

2. Log in using the username for the user with the black screen

3. Turn off compositing by running this command: kwriteconfig --file kwinrc --group Compositing --key Enabled false

4. Then reboot: sudo reboot

After rebooting everything should be ok.