SuSE 9.1 + quota = deadlock

we are running suse 9.1 using userquota but something strange happens when a user reaches his limit (for example with vsftpd). the task accessing the file hangs in state "D" - no access to the directory is possible. kill or killall won't help - only rebooting the machine helps until a user reaches his limit again... seems to be an old known bug - but this one should be already fixed?!? currently we are running: Linux version 2.6.5-7.201-default (geeko@buildhost) (gcc version 3.3.3 (SuSE Linux)) #1 Thu Aug 25 06:20:45 UTC 2005 please help - thank u!