sk450 apm 2.6 ac 3.1.5

I have an sk450 quad it flies great in stabilize and the land function works however the RTL and loiter cause it to toilet bowl after about 15secs basically it starts to hold its position good but then it gets worse iv done multiple compass calibrations and tried the latest 3.2.1 and nothing helps however I noticed this 3.1.5 code was a bit more loiter friendly but not alot I’ve attached my last log sorry its so big as I don’t know which part of the actual log is need to find my problem so ive uploaded it all with todays date 7/5/2015
ive seen multiple vids on youtube of better flying quads than mine in loiter so I know there is a fix just need to know what it is so please help I can upload pics if need be is my email or you can reply here as ive got the reply notify on, I signed up to this site today for help so please help

my quad
apm 2.6 ac 3.1.5
neo 6m gps
hobbyking sk450
escs multistar 20a (stock for an sk450)
motors 935kv 2213 (stock for an sk450)
2x3s nanotechs in parrell (2x2200mah=4400mah) I get 13mins or so depending on throttle abuse
rx tx are orange rx brand rx is 610 6ch tx is 6ch orange rx t-six