Pictuees too dark on 50D with 580EX - please help

...because I use my Canon 580EX on my 40D 50D and 60D with no problem...and there are so many settings that could be set wrong...my tip, I would call Canon Australia or I would visit a good camera store in Sydney...have them take a look and as you mentioned the flash works flawless on your other camera, so I am guessing that some setting in your 50D (flash control) is not right.

good luck to you and we will be lucky if we solve this problem over the internet.

Matthias