This site might be well known by some, but Canon has issued some service notices on the EOS 20D digital SLR. The most recent one is:
April 27, 2005: We have confirmed that the BG-E2 battery grip for the EOS 20D digital SLR camera causes issues such as the number of shots being limited or a low-battery warning being displayed immediately when used with a fully charged battery pack or a fresh set of AA batteries. Canon offers its sincerest apologies to all customers who have been inconvenienced by this issue.
The site is a bit optimistic. The 20D has had various minor and major issues (Err99 shutdowns; slight focus miscalibrations; etc.) that are not listed. I checked the Canon corporate website and the only cameras with service notices are:
If you know of other Canon sites (Japan/UK/etc.) or service notices from other manufacturers, please send it in as a comment to this page.
2005.05.20: Canon has just issued some service notices for their entire series of digital cameras. More information here.
Canon DSLR/lens has various problems and the customer support is doubtful. Most photo web link doesn't mention clearly, that Canon auto focus system for its DSLR and lens are sometimes non-precise and/or not matched (means before you calibrate all lens with the same body you may have problem). The Err99 is not only happen for battery back, and there are free service in other countries, yet seems not in USA.