I've pondered this as well, as I hang the rest of my bikes up in this manner. Whenever I ask this a lot of people tell me 'of course it'll be alright think of the forces that go through the frame when you ride it' but in my mind this is not the same as having the fork and shock bushings under a (albeit small) load in the exact same spot for extended periods of time (I don't ride my full sus that often). So it stays in the corner waiting for someone to provide actual evidence that it can join its brothers
storing suspension bikes in a non-horizontal position is a good idea for the suspension seals etc, below is a extract from my 2002 Rockshox Duke service manual:
I've seen forks leak oil out of the top seals, when upside down for any length of time. Modern forks may be better. It can also affect the damping, lockout may not work straight away
i hang my reba-equipped bike by one wheel from a ceiling hook, sometimes facing up, sometimes down. have been doing so for a couple years and have never had issues with fork function or leakage.
not so good for aston martins though, i remember one story where they had one hanging vertically on a wall and they actually sold it to a customer, he came back with it due to the car being somewhat screwed :roll: