Annoying BIOS problem

[crossbone]

I have an Intel DP67DE mobo with 2 SSDs and 2 HDDs. I installed the OS in only one of the SSDs and set the BIOS to boot from it by default. but every now and then, it automatically reorders the drive to boot from(it could be from a data-only HDD or the SDD with no OS). Even after resetting the order and saving it, I would still get the same problem at my 3rd or 4th boot. What could be the cause? More importantly, what's the remedy? Any help would be appreciated.
Thanks.

 

[StrangleHold]

Does it only happen on a cold boot? Does other setting change? Could be a sign of the boards battery going dead and not saving settings.