I have no idea what is causing this! You should be able to check the hardware clock with the command hwclock. Assuming that is OK, and since you must be compiling your own kernel to be on 2.6.12.3, have you compiled in the real time clock (CONFIG_RTC=m or y)?
I can see some other RTC related options in there which I'm not familiar with, but which might be worth a try.
Otherwise, happy new year