Good morning- Yesterday while shooting a wedding, I got an "Error 50" on my EOS 50D camera. The following is what happened prior to the message: - About 20 shots prior to the message, my partner inserted a Lexar 8 gb CF card that was giving him an error on his camera ("Error CF" on a 30D) We tried it on my camera and it said "card full". The card was nowhere near full but displayed the message. - I was using a Tamron 18-50 2.8 lens then switched to a Canon 10-20 lens. Got about 5 shots on that lens and then the "Error 50" message. - Camera is completely locked. You can hear what sounds to be the shutter moving everytime you open the battery hatch, the CF hatch, and when you remove the lens. After spending time researching the web for solutions, the following is what I have tried: - removed and reinstalled battery, lens, CF card, even the tiny dime size battery - cleaned the connections with alcohol/q-tip - tried different lenses, batteries, battery grips, no CF card, hooking up to computer for remote use - everything is disconnected to it now (after some needed sleep) I'm afraid that I will need to send to Canon but I thought I'd post here first. Any help would be greatly appreciated! Thank you so much.