Sansa Clip - "Remaining" battery not correct

Wondering if anyone else has this issue.  My 4GB clip says Remaining 66% when I plug into my computer.  The Clip itself shows “connected” and appeards to be charging (battery icon on the clip signifies it’s charging).   I can leave this attached for hours, but it always says 66% on the computer.   Once I disconnect the clip, the battery Icon on it shows “full”.  Sometimes, the "reamining will say “critically low” on the computer, but after it charges for awhile the clip shows a “full” battery indicator.  The clip has the latest firmware.

Thanks