Linux Newbie: USB Drive Freezes Computer

[clearasmud]

I am new to GNU/Linux and have recently installed Debian 2.6.8-2-386 standard distribution on an old (circa 2000) Gateway Select Athlon 1 GHz PC. It has USB 1.1 controller. If I plug on a USB flash drive, the computer instantly freezes and never comes back. I have to manually power off and on again. I discovered that if I modprobe -r ohci_hcd, I can plug on the flash drive without a freeze but nothing else happens. Next, I installed Debian usbmount package but this did not fix the problem. I discovered that if I remove ohci_hcd, plug in the flash drive, then modprobe ohci_hcd, the flash drive is recognized. I get an icon on the desktop and nautilus window pops up. However, if I remove the flash drive, I must remove ohci_hcd and sd_mod modules before plugging the drive on again. I remove sd_mod module because otherwise the drive is not automatically recognized when I plug it in the second time.

I have Googled for this problem but cannot find anything and am out of ideas at this point. Hopefully someone smarter than I knows what to do.

[clearasmud]

My PC has AMD-756 [Viper] USB (rev 06) controller which apparently has some kind of USB bug. Maybe that's why it is flaky. Could there be a patch for OHCI specifically for this controller?

[clearasmud]

Checking the syslog file, I found an entry that said ACPI is not enabled because the BIOS is from 1999 and too old. The next line said to use acpi=force as a kernel boot option to enable it anyway. Being desperate for anything that might work, I enabled it and rebooted the machine. Now ohci_hcd does not freeze the computer and USB device mounts fine! The syslog now warns "The ACPI AML in your computer contains errors, please nag the manufacturer to correct it." But so far the machine is working fine.

The sd_mod problem was solved by adding "vfat" to the FILESYSTEMS parameter in the /etc/usbmount/usbmount.conf file.

This must be a very rare problem since no one had any advice on what to do.