boot seats

hi i have a 2001 discovery td5. the seats in the boot. i took them out to gain more space . i have now put one back in. when the seat is folded down from the stowing position. the back rest part wont come up . i can get the backrest part up if i trip the bottom catch which locks to the floor but the bottom catch wont latch to the floor. when the bottom part latches to the floor it sems to lock but obviosly not enough i have spent about 30 minets standing on my head and getting nowhere. i have searched the posts but cant find anything . help.