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.