"The issue is being intensely investigated right now by Service & Support Engineering, and they have not yet determined the root cause. They are leaning toward a software problem with the Drive Setup software since the problem can be reproduced on different hardware platforms and IDE drives of different vendors. Because of this, customers should not be replacing or reformatting the hard drives. They also need to be backing up files frequently as there have been reports of data loss on the drives.
Until a root cause is identified and the problem fixed, we recommends that users use the Sleep command rather than Shut Down when done with the computer. They should not downgrade to OS 7.6.1."
This is similar to advice previously posted on Apple's Discussion Boards. However, this advice may be partially superseded by new information posted on the Discussion board that implicates two new possible causes of the problem:
"We have two possible theories being tested at the moment. One of them involves the 5500/6500 ATA Update extension (separate extension under Mac OS 7.6/7.61, but rolled into OS 8). If you have reverted back to 7.6 or 7.6.1 to avoid this issue, please make sure you do not have this extension installed.
The other is that virtual memory seems to trigger it as well. If you do not want to leave your computer on all the time, then turn virtual memory off. We have several computers running now with virtual memory off that previously saw the error, but have not failed since we turned virtual memory off."
I have gotten email from several readers confirming both of the 5500/6500 ATA Update extension and virtual memory as possible causes. It looks like Apple is on to something here. Finally, Brian Hartmann offered an (unconfirmed) suggestion that having a CD-ROM disc in the drive at startup appeared to increase the likelihood of the startup problem occurring.
Related virtual memory issues This virtual-memory-off work-around is of course separate from the problem some users have reported (see previous item), where virtual memory cannot be enabled at all. It is similarly separate from some startup problems attributed to virtual memory being on (as described previously)!! Is this complicated enough for you?
The 1.2Gb IDE drive blinking ? problem Another recent posting on Apple's Discussion Boards now indicates (contrary to a previous Board posting, as reported here) that a firmware updater for a different blinking question mark problem, this one related to certain 1.2Gb IDE drives on some Mac models, will be released after all. It adds: "The firmware updater has a good chance of preventing data loss, so if you have a drive suffering this issue that has critical data on it, or if you do not need to get the drive up and running again, you can wait for the updater and get the drive back that way. If you have a good backup, or need to get up and running now, go ahead and have your service provider replace the drive now."
I hope to have a summary item on all of these blinking question mark startup issues by some time next week.