MSI Wind U120 - 45 mins on 3 cell battery?

I suggested my sister get an MSI Wind U120 less than a year ago, as it was on sale and at the time, the unit looked good versus the competition's at the price. I made adjustments so it would save as much bettery life as possible, it lasted about 1.75 hours (1:45), she loved it, carried it around her house everywhere she went, life is good.

Fast forward, almost a full year, and she's now only getting 45 minutes on the unit and there's no change in configuration that would drain it faster. I'd expect a battery to remain consistent over a year, if not three.

Is this normal behaviour for this particular model of MSI's Wind with 3 cell? The warranty runs out in 7 days... is this something that can be taken care of while under warranty?

Thanks in advance!