580EXII Memory Setting problem.

I have 2 units of 580EX II and 1 ST-E2. I was working on the other day with those units where the 580 EX II's are configured as slaves. Everything was fine when suddenly one of the 580 EX II's red light (it blinks when it is configured as slaves) stop blinking after I took a shot. Well, I thought it was just a small problem. I turned the unit off and on again. After putting it into slave mode, I began shooting again. It happened again, the 580EX II just went back into a normal mode. I also noticed that, if I configured this unit as a Master unit, it will retained this setting after I turned the unit off and on again. But, if I configured it as slave, it just lost the setting if I turned it off and on again. The other 580EX II worked just fine. Anyone has experienced similar problem before?

This is just a wild guess but I'd double-check to make sure the batteries are in good shape.

Agree with Curtis. Mine stop blinking when the batteries get low.

Thanks for the reply. I just tested with a brand new set of batteries, it still does the some. Well, I guess, this unit is broken. I will turned it in for repair. Fortunately, it is under warranty.