That appears to be a long standing bug, apparently, very hard to diagnose, cause nothing is logged. The Broadcom STA driver seems to be the cause, and it being closed source probably doesn't help.
Originally Posted by VeeDubb
I guess the best you can do is file another bug report:
Another option is to try the latest driver from http://www.broadcom.com/support/802.11/linux_sta.php
Update: Here is another bit of info that might help: