Got the dreaded err99 issue on my 40D yesterday.
Looked at all the threads here and tried all the tricks suggested including removing all accessories, charging my batteries, trying different modes, live view. The error still persists though and I will be calling Canon tonight to send it in.
The warranty is up and so I'll end up paying lots (
Can anybody who had this problem and got it fixed without sending it to Canon suggest any other alternative I may have missed?