I found this solution for this bug... it has worked for me so far:
Go to System --> Administration --> Software Sources and select the Third-Party Software tab. Click on Add and enter the following line:
Then click on Add again and enter the following line:
Click on Close, then on Reload. Shortly your software updater will indicate that there are updates available for compiz. Install them, restart your machine and you are done.
credit here goes to mario limoncello which came up with this fix and published it on launchpad