It would be nice to know what these error codes mean without reinventing the wheel. I got Error 22 yesterday and it threw me for a minute. Having now had my camera give me a message that is not in the owners manual I would also like some response from Canon on this. I replaced the battery in the grip in and the error went away. Sorry for the delayed reply.
Hernia surgery has a way of putting people out of commission for a while.
The good news is, I seem to be recovering on schedule. This error occurs when the EOS D30's self-checking system processing time has exceeded the specified limit. This error can occur when several switches are pressed at the same time. If this does not solve the problem, have the EOS D30 examined by a qualified service technician. This error occurs when image data cannot be written to the CF card.