Astroflight 109 HELP

brian, the psu i have isn't a modified computer psu. it's this one: http://www.rcgroups.com/forums/showthread.php?t=646923
(best link i could find sorry)

both packs are charged, and when the first one finished, i put the 505 guard on it, and cells 2-4 are discharging.. well the second pack finished, and the first pack is still flashing cells 2-4..
this was the first time ever charging the packs, so is that maybe the reason it's taking so long to balance? how long should it take to balance 5 4000mah cells? i think i might try a parking lot tonight, as the sun has set.. but i don't want to run them till they're balanced.. what a waiting game :(