Comment 17 for bug 43745

There seem to be two phases to the problem on my Inspiron 6400 with kernel 2.6.15-22.686

* something corrupts the RTC or BIOS NV data. This might be when the hwclock is written at shutdown. [1]

* as long as the BIOS does not do a full verify during POST, it loads the MBR and booting continues as normal. However, something has failed because the grub timer does not count down, and the time displayed on the Gnome panel is incorrect. [2]

* if, however, the BIOS does do a full verify, then it detects the corruption and halts with the 'Time-of-day clock stopped' error. [3]

Notes:

[1] Last night, I was running Celestia. It crashed badly (touchpad, keyboard and USB mouse were not responsive, gdm would not restart and I could not select a tty) and I had to use the power button to turn off. I don't know if this would have written the hardware clock. On another occasion, I tried to do a sleep and/or hibernate and got a coma instead. I had to remove AC power and main battery to recover. But perhaps sleep/hibernate also write to hwclock?

[2] If you notice the grub timer has frozen, you can still use the keyboard to select a kernel/OS in the grub menu and boot that way. If you boot into Windows XP, WinXP seems to do something to restore the BIOS settings to normality.

[3] and you replace the motherboard. Some people have reported success by removing the coin-cell battery, but others have not.