There is a service advisory out from Nikon USA on these.. Appears there is an auto focus issue with some of them.
click here to obtain service authorization.
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Compatibility Issues (swiped from
here)
The N55 is compatible with the AF, AF-D, and AF-G series lenses, as well as the few manual focus AI-P lenses with built-in CPU chip. However, you cannot use other manual focus lenses on this camera. Note, too, that the N55 does not provide autofocus with AF-S lenses and cannot support the Vibration Reduction feature of VR lenses. All of this is understandable in an entry-level model.
Another thing to look at may be a shutter that covers the viewfinder when one uses a timer on a tri pod and your eye would not cover the rear eye piece. I vote for a bad battery myself. What is interesting is that neither google, Nikon USA nor yahoo turn up an online version of the manual.