That usually means the battery that powers the CMOS is going and needs to be replaced. It's important because it keeps track of information the computer needs in order to boot up properly. They're pretty inexpensive and easy to replace if you've ever upgraded anything in your computer before. You can get the battery at Radio Shack, or maybe the big-box office-supply stores.
ETA: Just noticed you said the computer was pretty new, so this probably doesn't apply to your problem, but I'll leave the comment here in case it might help someone else