Airbag/Horn incident

[Brute6]

Had an interesting incident happen with my Ute yesterday.... It was sitting in the driveway, no one in it or near it, and my horn went off for about 10 seconds then stopped. About a minute later, the horn went off again, for another 10 or so seconds.
And after about 5 minutes of wondering what the hell was going on, the horn went off again, this time it didn't stop. So after about 3 or 4 minutes, I popped the bonnet and removed the horn fuse and it stopped.
Confused, I opened the drivers door, and the steering wheel cover is now very loose, and spongy, and not nice and firm like usual? And not wanting to play with an airbagged Steering wheel, I'm a little worried about it going off now.....

So now, the car is at the Dealers (regretfully.......) to find the source of the problem.
I've been told that it could be a heat issue, and that something may have broken behind the actual airbag, and is now resting on the horn activator?

Has anyone had this happen to them before???