problems with hotshoe cable flash

bonjour

i got a canon off camera shoe cord 2 and i am using a 380ex with canon 400d
when the flash is on the camera itself it works fine but when used with the cord pictures come washes out overexposed i have tried diffrent setting av p m all the modes but cant figure out what i am doing wronge can you guy help me ,

cheers

It really should work the same way.

Inspect all of the contacts on the cord and make sure they're clean and in good order.