Date/Time Error After Dual Boot setup

I apologize if this is not the right forum... couldn't figure out just where to place this.

I have a older Dell Precision 690 workstation that is setup and running XPx64 for ages.  Today, I converted it to a dual-boot system booting between XPx64 and Win7.  This system has several drives in it with the XPx64 OS on drive C.  I made room on the C-Drive for another partition and used Genome Partition Editor to place the new partition on the drive... it worked great and I had a new partition to install Win7 on.

After rebooting several times to make things kosher on the disk, I started to get an error during BIOS boot up about the date and time being wrong. (I use this system daily for years and never had this error and was a bit suspicious about it being too coincidental with the partiion resize, etc.)

After some research on the web, it pointed to the system battery going bad.  This seemed logical as the system is 7 years old.  I continued on and successfully installed Win7 and the dual-boot is working fine and proceeded to start the process of installing Win7 updates and I will be continuing to install apps, etc.

But repeatedly, the date/time error has been popping up in the BIOS.  I can boot several time without the error happening... but then on the 3rd or 4th boot, it will happen again.   I have reset the date/time in the BIOS repeatedly, but the error keeps happening.  Finally, I replaced the battery thinking that it was the cause.  I rebooted and Win7 started properly... but then the next time I rebooted the error happened again.  The new battery I used was recently purchased... so I don't think it's the battery.


Any ideas what might have caused this error to start popping up?

Thanks for any ideas!