One of our Blackberry users complained that the bluetooth connection between the device and his AUDI became unstable for some reason.

He sent me an error message saying: Uncaught exception:java.lang.ClassCastException

I googled for this error message an found an entry in www.blackberryforums.com saying that this error could be caused by adding a group to the personal addressbook. Hard to believe but nowadays nothing seems to be impossible. I phoned the user and asked if he recently added a group to his addressbook. He confirmed. So I asked him to delete the group and to try bluetooth again.

Today he confirmed that after deleting the group from his addressbook, the bluetooth connection works again.

The device is a BB 8800 running with firmware 4.2.1.101. As the forum thread is from 2006, I guess that this error is already fixed in a newer firmware version. Have to check this.