Dell Studio XPS 435MT won't start with a CMOS Battery in the computer

My computer has performed beautifully for 3 years.  While I don't have a UPS, I do use a very heavy duty surge protector which has never caused any problems.  Yesterday I had a power outage.  The computer wouldn't start up afterwards.  Upon pressing power, I get a brief orange light on the power button, the fan moves about an inch or so, then nothing.  I searched online and tried removing the CMOS Battery.  That worked and the computer started up again (with no replacement CMOS battery).  I then added back a new CMOS battery (yes, I used the same type of battery), and the computer won't start again (same symptoms).  Remove the CMOS battery, and it works again. 

Does this mean that my motherboard needs replacing?  I wouldn't think so since it works fine without a CMOS battery, but that is annoying because I have to reset my date and time, and some dependent software registrations, each time I boot my computer.

Is there something else I need to do to get the computer to accept a new CMOS battery?

Thanks for any suggestions!