Here's a little heads-up concerning Classic. Do not move an OS 9.2.2 System folder from another computer to a 10.4 Mac. This will confuse Spotlight (it will crash trying to index the other non-extistent computer). Also, in the Advanced section of the Classic preferences panel, check the 'Use Mac OS 9 preferences from your home folder' box. Install a new System folder from an OS 9.2.2 install disk, and you'll be good to go.
[robg adds: I can't confirm this glitch, as I no longer have Classic installed on any of my machines. If someone can confirm or deny, I'd appreciate it.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=2005092917445498