I think I figured out the problem. After consulting with the LHS "expert", he checked the resistance on my series connector - it was good (<0.002 ohms), he recommended cycle charging the battery. I put it through a complete Discharge/Charge cycle (both NiMh batteries) and ran it today for ~11 minutes. That's 5 times more run time than before.

I never really noticed how many amps were going into the packs before, but I figure it could not have been near capacity. I'll cycle the batteries one more time in hopes of improving runtime.

As for the Flightpower 4s. I finally got a hold of the correct balance connector for my charger and when I hooked everything up, commenced the charge, nothing happened. It said that the charge was complete. I noticed that the pack had become puffy on both sides and decided to call Flightpower. They told me to destroy the battery (bucket of water and 1 cup salt) and that a new one was in the mail - great customer service.