After upgrading to Panther I started seeing a very noticeable performance problem that only occurred after having a second user log in. After some searching I traced the problem to the All in One driver for my PSC 1210 printer/scanner/copier. The performance issue was due to thousands of USB errors being written to the system log. Removing the HP driver stack and installing Apples printer only driver got me printing again but no dice on the scanner driver. Has anyone else found something that works?