Off camera flash underexposure

I've had this same problem with mine (version2) and I always thought the lock wheel wasn't tight enough! OOPS!

Yeah, I got the same thing...but that doesn't explain why my list of 15 photographers so far with the same problem keeps growing. I made the mistake of buying 2 of them at the same time and they both do it whether on camera or off on a bracket/camera cord..when I asked how much it would cost to repair it or if there is a cost to check it out..well, I'm still waiting for a response on that after asking 3 times. I tried different tightenings, batteries, etc..nothing gets me more than 10 flashes before it starts acting up.

Yeah, I got the same thing...but that doesn't explain why my list of 15 photographers so far with the same problem keeps growing. I made the mistake of buying 2 of them at the same time and they both do it whether on camera or off on a bracket/camera cord..when I asked how much it would cost to repair it or if there is a cost to check it out..well, I'm still waiting for a response on that after asking 3 times. I tried different tightenings, batteries, etc..nothing gets me more than 10 flashes before it starts acting up and mine is the 2nd. module with the Rebel XT sticker on it. Oh well, looks like it is back to the 283 Vivitar.