1999 Range Rover suspension question

I have a friend who just bought a 1999 Range Rover with an air bag suspension and she has a question that I don't know anything about. I figured that someone here on the forum would own one, or know the answer to the question. What is the deal with the compressor for the air springs? I just took the car for a drive, and it seems like the compressor is running an awful lot. She says that it really only runs that much around town, but once the car gets going and settles down to it's highway stance she doesn't hear the noise. It could be that she doesn't notice it because of the radio/ wind/ highway noise. My worry is that one of the air springs may have a leak in it so the compressor has to work more often to keep the air tank filled.

Does anyone know how the air suspension in a 1999 Range Rover is supposed to work? Should the compressor run fairly regularly, or should it only run on start up to jack the truck up?

On a side note; it was super cool to feel the truck raise and lower itself. Now I want a set up like this in the VX.

If the compressor keeps kicking on then there is most likely a leak somewhere - it may be one of the bags, or one of the lines, or one of the fittings. It should have no trouble maintaining it's ride height throughout the day. Maybe the switch is stuck to the offroad stance so it's always trying to "lift" it past it's city stance?

Go to landroverline.com and click on tech tips, scoll down ,tons of info-I think most people change out the whole air bag system.

LOL, i cant believe im about to make this comparison, but here it goes,....our oldsmobile shilloette has the compressor suspension, it does fine, but a drawback about the olds system, dont know about the RR, is putting a hitch on it. the family and i were going to go out west, and pull our trailer, and see all stuff out there.....well, we were told that we couldnt put a hitch on the olds, cause the compressor would be running all the time, trying to keep the van level, and it would ruin our suspension.
hey, its late, i havent slept well in days, hope you got a chuckle, but i always wonder.
so i guess im asking, could a hitch be put on the RR?? or any other vehicle with the compressor suspension??

A bit late to answer as you've probably already found the info but anyway:
The air suspension is speed sensitive i.e. if you go over a certain speed it will automatically lower to keep the C of G down then when you go slower it pumps back up in rediness for rough terrain therefore if you're going round town it will be up and down all the time but if you're on a long run it will stay constant. You can override it to the low setting but not to the high setting for safety reasons. It also has a super low setting for carparks or people getting out.