When I shot with my 10D connected to the Speedotron power pack with a synic cord(and making sure the polarity is right,which was anter issue). I was able to fire the strobs with no problem. But when I connect the camera to the computer and used the zoombrowser to shoot the camera would not fire the strobs and gave me an error message. Very frustrating. I've had to use a small flash on the camera to trigger the speedo packs to fire them. I've tried to explane the problem to canon with no resolts. Seems there pat answer is send it in for repair??? Oh,I also tryed with Norman packs,same problem. Anyone having this same problem? Or any salutions. (I have gotten the Wein 6v adapter but this did not solve the problem). Any help would be appreciated.