G10 photos? Don't call MUFON, hit up your local Canon repair center. The company is acknowledging an issue that results in small, horizontal defects like that pictured above. Apparently such aberrations seem to appear at random, regardless of camera settings, but the affected units' serial numbers are at least easy to pick out at the read link. Not exactly good news for Canon, hot on the heels of the 50D vertical banding fix, but at least it isn't attempting some sort of cover-up.
Update: LimeyHoya commented to let us know Canon USA has posted up the same notice, meaning you can now figure out if you're affected without having to ponder any abstract Google Translate koans.