I had some issues with a 580EX II hotshoe foot coming loose. It became so loose over time that the flash started losing communication with the camera. Symptoms included chronic E-TTL overexposure and lack of in-camera menu control.
The fix was simple and took about 45 minutes. It would have taken 20 minutes but I got into a fight with the quick-release button spring 
Click the following link or the image below to head over to the step-by-step repair process, complete with photos and a time-lapse video: http://blog.soskiphoto.com …-hotshoe-canon-580ex.html
