Well, it does seem likely that something in the backup could be causing problems; obviously, make sure you are using the very latest version of your backup software. Some people have also found that installing the Combo OS updaters over the newest version will sometimes resolve problems seen after installing the Delta installer. You might try using a different drive. Especially, if it's possible, something on a different interface. Changing to Firewire 400 might be enough to stop it, or you could see if a USB 2.0 drive has the same problems. Or, just downgrade to 10.4.3. ;-) Of course, you might want to run DiskWarrior on both drives (or at least Disk Utility), and repair permissions too. You can find the 10.4.4 Combo installer here: http://www.apple.com/support/downloads/macosxupdate1044combo.html Personally, I haven't had any major problems; I synced my 2G iPod once with no problems, and I use a FireWire EyeTV every day... But no backup software or external drives. I did have an issue with SystemUIServer hanging about once a day; I deleted its preferences and rebooted and it hasn't had any problems since. However, it could have also been caused by my iPod; some people have seen SystemUIServer hang with an iPod plugged in, but start working when the iPod is removed. I didn't learn of that issue until after I took the iPod back to my office, and I haven't tested it since. "Dr Trevor J. Hutley" <TrevorHutley at consultant.com> writes: > Since upgrading to 10.4.4 (day of issue) I have had quite a few cases > now where the screen brightness is not responsive, and the computer > is blocked. ... > I also saw: > > com.apple.iokit.IOSCSIReducedBlockCommandsDevice(1.4.4)@0x2eafc000 > dependency: com.apple.iokit.IOSCSIArchitectureModelFamily > (1.4.4)@0x584000 > dependency: com.apple.iokit.IOStorageFamily(1.5)@0x49f000 > com.faronics.driver.DFXDriver(2.0.48)@0x7ef000 > dependency: com.apple.iokit.IOStorageFamily(1.5)@0x49f000 > com.apple.iokit.IOStorageFamily(1.5)@0x49f000 > > all of which seem to relate to input and output. > > Does anyone have any idea if this PANIC s due to anything I am doing?