My new P500 BIOS is displaying the wrong time. It is usually four hours ahead. I can always set it back. However, it jumps back ahead again by 4 hours by itself. This causes problems within my Win7 x64 OS.
I do not see any BIOS firmware updates either to address the problem. I have Ubuntu 12.04 for work and Windows 7 for everything else. I do not see how an operating system(OS) can effect the BIOS though.
When running two operating systems, there will be a tendency of this happening. This is most visible when dual-booting Linux (Ubuntu) alongside Windows. You will notice this after running Linux, then going back to Windows.
The reason for this is that Ubuntu wants the BIOS clock to be UTC and adds an offset. Windows just uses the actual BIOS clock. The OS can modify the BIOS clock.
Here's an Askubuntu thread that describes the same situation and offers a solution. (Edit /etc/default/rcS and change the line that says UTC=yes to UTC=no.)