Reverse rebound

[jaffacake]

This really is turning out to be the rc build from hell!!
New problem...built the shocks, filled with oil,set the rebound with the 4mm of spacers as per tip on the Durango site, when i pull the shaft out of the shock body fully it wants to travel back up into the body,i have the oil domed at the top of the body when i screw the cap on & im letting the shocks stand for the air bubbles to disapate
There is a comment on the Durango site describing exactly this problem but no answer to it
I have tried & tried again but cant get it right, built many 1/10th & 1/8th shocks,never come across this before..HELP!