Thanks for your help. I dug out the manual and found a jumper called "Clear RTC RAM" which had a reset procedure exactly as you guys described - power off, remove battery, change jumper to alternate pin setting for 5-10 seconds, replace battery and power up. This procedure is supposed to clear CMOS memory of date, time, and system setup parameters according to the manual.
Battery checked out at 3.10V. Anyway, did all that, powered up again, and now I don't even have the voice report on the POST. Just constant hard-drive access, which sort of worries me - don't know why it would want data from the harddisk if it hasn't even made it through the POST yet.