Have you got an equalizing trey. by taking your battieries down to 5.4 is okay. you should also equalize them also.
I've have heard some really good things about your charger. Just curious what software is in it? Did you purchase it new our used?
By chance do you have the intensire system for the charger. If you do I would try that out.
Also how old is your pack. they should take more then 2700. what do the voltage peak at? I should say on the charger when it is done.
You might also want to make sure all your solder joint on the pack a1 condition.
Well I hope this helps.