I found that my Canon 7D does work and that's great. I used the same cable and never did have anything else plugged in. I think that points to something going on with the updates for the 5D. I don't feel confident that the download worked since I've never done an update before and it seems like I should be able to find it somewhere or have to do something to activate it. Can someone tell me what I need to do after downloading the update to get it working? Maybe nothing but just wondering.
thanks for your ideas/
Laura