Hi,
I recently set my 7d up to shoot infra red with my 430EXii which I did ok. I went to use it the other day and couldnt get my on board fllash to pop up to trigger the external flash.
When I go into my cameras menu my flash control is set to enable but when I go through the rest of the menu I get "This menu cannot be displayed. External flash is attached" This is when I have no flash either attached or switched on in the vicinity of my camera.
I can get the 430's red blinking light ok, the pop up will just not operate even if I put camera in full auto and press the button to operate the on board flash. Any ideas anyone, Ive probably done something really stupid 
Thanks


