Internal failure of the rear cargo door latch can cause the door to not open when using the outside door handle.Google+
Car Problem Reports
Land Rover Discovery Door Won't Open Due to Internal Failure of Rear Cargo Door Latch
Land Rover Discovery Problem
Average Mileage: 95,913 mi (12,400 mi - 207,000 mi)
Rear door would not open inside or out. I fixed the problem. The outside handle was frozen inward.I took a screwdriver and on the side of the handle (not under the center, but on the side using friction)
GENTLY got it back to the position that would open the door. It opened. I then sprayed WD 40 in a small hole above the latch on the side of the door (located by the child lock lever)
It apears to work fine now.
Visitor, 1995 Land Rover Discovery, 110,000 mi
Cargo door won't open from inside or out.
Removed the Land Rover plastic logo from the rear door latch, and sprayed WD-40 in there.
Visitor, 1994 Land Rover Discovery, 65,000 mi
Back door would not open.Screwdriver and WD-40 fixed the problem.
Visitor, 2003 Land Rover Discovery, 105,300 mi
Rear door won't open
Visitor, 2004 Land Rover Discovery, 48,409 mi
door will not open from inside or outside. outside handle now has little movememt. no warning
Visitor, 1997 Land Rover Discovery, 65,000 mi
back hatch door only open with key. Door will not open normally. Need to replace door mechanisms whatever they are, have not done so yet.
Visitor, 2001 Land Rover Discovery, 105,000 mi
Sprayed inside latch with silicone spray to lubricate.
When I turn off the car the lock in the rear door goes crazy and then will not open. It stays locked???