Error 99

[SnowA]

I got one for the first time today on my 30D - and got it several times. Kind of freaked me out at first.

Googling, I found this useful blog post (look at update #2) - http://www.richardsnotes.org/archives/2005/04/29/50mm-lens-contact-points/

Mine seems to have resolved itself with cleaning the lens contacts on both lens and body.

Hope it helps.

[ricktas]

common and well know problem. We get a thread on it about once a month or so.