I have a PowerMac G4 that I got recently. It booted and worked fine, I put on new users and deleted the old ones. Now it won't boot. I can get into Open Firmware and FireWire Target Disk mode (I don't actually have a FW cable though). It will not boot to disk or CD. Booting to disk gives me the multilingual "You need to restart your computer" kernel panic, and booting to CD either gives me that or a gray "no" symbol. Verbose boot reveals the "loadable modules in backtrace" to be com.apple.driver.AppleUSBOHCI and com.apple.iokit.IOUSBFamily; so, it seems to be a USB issue, but my only USB devices attached are the keyboard and mouse. Does anyone have any idea what I can do?