Hello, I have been working with about twenty Scientific Linux machines for around five months, and in that time I have seen a complete USB failure on two different systems. Some of our systems have USB mouses attached which generally work fine. "Mouse not working" (the mouse 'freezes') is the fault reported by the users, but I think the problem is with all of the system USB capabilities. Some of the details of the latest failure are: In "/var/log/messages": Feb 28 11:38:56 sysname kernel: drivers/usb/input/hid-core.c: not resubmitting, input0 Feb 28 11:38:57 sysname kernel: hub 1-0:1.0: connect-debounce failed, port 5 disabled Feb 28 11:38:59 sysname kernel: hub 1-0:1.0: connect-debounce failed, port 6 disabled Feb 28 11:38:59 sysname kernel: hub 2-0:1.0: port 2 disabled by hub (EMI?), re-enabling... Feb 28 11:38:59 sysname kernel: usb 2-2: USB disconnect, address 2 Feb 28 11:39:01 sysname kernel: hub 1-0:1.0: connect-debounce failed, port 5 disabled Feb 28 11:39:02 sysname kernel: hub 1-0:1.0: connect-debounce failed, port 6 disabled (with the last two messages being repeated continuously.) The last two messages also fill the system "dmesg" file. The two systems that have experienced the failure have been running SL 4.1 and SL 4.4 and have different hardware (a two year old Dell and a 5 month old Viglen) so I think the chances of hardware incompatibility are minimal. (Besides, there are plenty of similar systems here using USB without problems, and the two systems that have experienced failure are usually OK.) I have used "system-config-mouse" to check that the system has recognised the mouse correctly. It recognises a USB scroll mouse which is exactly what is in use. A reboot fixes the problem, but without a mouse to close applications cleanly, data is lost. Reboot to fix is not an ideal solution either! I was wondering if anyone else had experienced similar, and more importantly if they found a cause and solution. (I have seen in the list archive a similar problem reported, but the solution was to swap to a PS/2 mouse. I do not have enough PS/2 mice to replace all of our USB mice, and this does not help a user wanting to use a USB stick drive etc.) Any solution, or advice on where to look for more information that might point to a cause would be appreciated. Thanks, Jon -- ---------------------------- Jon Clark Scientific Officer Dept. of Applied Mathematics University of Sheffield Sheffield, S3 7RH, UK ----------------------------