My Sputnik has developed a problem. The x-sync has started acting odd. Occasionally it will actually fire the flash when the shutter trips. Most often, it doesn't. I've tested it on a flash (Rollei E36RE) and flashbulbs. Same result. If I set the shutter to bulb, the flash fires every time. But, on 1/15, 1/30, 1/60, 1/125th, etc, it doesn't trip. The odd thing is that on the flashgun, I can see the ready light flicker when the shutter fires. If I open up the lens to watch the action, I can see the arm make contact with the x-sync post, spark, and then pull away. Since it is sparking (and the flash ready light flickers), I know it is making contact. Why doesn't it fire? How can I fix it? I've tried contact cleaner on all surfaces as well as a bit of abrasion to improve the contact surfaces. No luck so far.