Land Rover used to ship all the vehicles with about 50psi in all the tyres just to stop that very problem, and there was also a bulletin quite a few years ago about one particular sort of tyre (Goodyears I think) "flat spotting"on vehicles in hot countries if the vehicles were in storage for a while.
I've even noticed it on my Discovery, if the vehicle is parked up for a week or two, you sometimes get a bit of a wobble in the steering for a while but it soon goes away. Crossply tyres are much worse, I drove a vehicle with a set of General SAG xply 7.50s on a few years ago and I thought the damn thing had square wheels on, it had been sitting for a couple of weeks, but after a couple of miles it was fine. I guess it's why they used to say you should jack up vehicles that are in storage...