Hello mate, if your moving the seat "back" into it's upright position before sliding the base backwards then it will lock in that position. in other words the base needs to be slid back before the upright pushed back if that makes sense? 
i get that but thats not the problem, when the upright is down and i push the base back it shoud lock/stop in the position it was before but it dosent, it slides all the way back to the end of the run so i have to sit in it and adjust it again! any ideas?
