AW ICR123s and PH-123A-A charger

I recently bought a pair of AW ICR 123 protected batteries (blue, silver label with red stripe; 3.7v, 750mAh) and a PH123A-A charger (output 4.2v, 360 mA) from a member on CPF. Both batteries were around 3.8v to 4v when I got them maybe 6 months ago or so. I have tried to read up on Lithium Ion batteries but this is my first time using them.

I had been using one of the batteries in a Lumapower IncenDio flashlight (used occasionally) and last night the flashlight suddenly turned off (no dimming or gradual decrease in brightness, just turned off). I took the battery out and measured the voltage at 3.28v. I was going to put the other battery in the light, but when I measured it, it read 0.00v. I assume somehow the protection circuit was tripped, since I cannot imagine it simply discharged to that voltage.

I hope maybe someone can answer a couple of questions for me. I cannot find any manual or
instructions online for the charger. Don't know who the Mfr is; it seems to be sold under different names when I Google it. One is here: http://tinyurl.com/4shrwl7

Does anyone know if this charger require me to charge two batteries at once, or may I charge only one at a time?

If I have to charge two at at time, is it correct that they should be close in voltage when I charge them? (I assume this is the case since there is only one LED indicator light)

If so, what do you suggest I do with the batteries, since one measures 0.00v and the other
measures 3.28v?

What method do you suggest to "reset" the protection circuit in the battery that measures 0.00 v?

Thanks all.

Protection circuits are usually persuaded to reset by charging the cell. If that doesn't work, then there may be some other problem with the cell. But I'd try to charge it first - preferably at the lowest current possible if you can change the current used. If not, don't worry about it.