This led David Werblo to pose an equally interesting question: If the problem is really dependent on the OS, how does the Mac "know" what OS is in use at the time the startup delay occurs? People describe this problem as occurring almost immediately upon turning on the Mac, before the hard drive even spins up. Shouldn't this mean that the Mac has not yet identified the OS in use? If so...the mystery deepens (although I suppose it could be a difference in what is stored in PRAM across different OS's). Stay tuned.
A possible work-around Meanwhile, Chris Kurn claims to have found a simple and reliable work-around to this problem. I cannot confirm it as yet, but I expect I will be hearing from readers on this matter. Here it is:
As soon as you turn the Macintosh on (!), force the computer to attempt to startup from a CD-ROM disc (even though no disc is present) by holding down the "c" key or by using "Command-Option-Shift-Delete." Chris says this will result in an "instant" boot up rather than the 30 second or so delay.
Update: Bob O'Driscoll writes that this did not work for him.
No permanent fix in sight? Finally, a reader using the latest beta version of the forthcoming Mac OS 8.1 claims that the new update does not yet fix this problem. Alas.
Update: Another reader claims that 8.1 did fix the problem for him. Guess we will have to wait and see.