cause of Err99 messages involve EF-S 18–55 lenses (kit lens for the 350D and 20D) that are defective; purchasing used EF-S 18–55 lenses is a risk factor, especially from eBay auctions. Some auction listings state that the lens was never used – especially those claiming that the lens was originally part of an EOS 400D kit; the best way is to verify the serial numbers indicating the manufacture date. Firmware updates The latest firmware released by Canon for the EOS 350D is version 1.0.3 (released 27 October 2005). It fixes problems relating to remote release cables, as well as a problem while reviewing saved images. See also Canon EF lens mount Canon EF-S lens mount References External links Canon EOS system infopage 350D Cameras introduced in 2005