Downloaded the new OS10 update for my G5 PowerMac as soon as it appeared on my screen. What a nightmare! Upon rebooting, I lost my two WD firewire external hard drives, plus my firewire scanner and Epson printer. Spent four hours on the phone yesterday morning with Apple tech support, Adobe, Extensis, local techie, etc. Apple's advice was to reinstall the original operating system, which played havoc with all preferences, etc. for Adobe CS2 and Acrobat, Quark, Suitcase Fusion -- just everything. A day later, I am still not back to normal. BEWARE! I had a perfectly fine working machine until I downloaded the 10.4.9 update!