biggurs

hi everyone
I recently bought a 2004 530d with full dealer bmsh.
Its in really nice condition and is fully loaded. Its been looked after v well but I tried blowing the horn the other day but it didnt work so I checked the fuse box in the glove compartment and noticed the fuse for the horn was missing. I suddenly then realised there was a fuse in the glove box which just happened to be the correct type. I put the fuse in and checked the hoen and it was working. Few days later I went to start the car to go to work and as iput the key in the ignition the horn went off and did not go off untill i took the key out. Anyway I started the engine and then it went off. when I started the car up on the way home from work it was all fine, no probs.
The next day the horn went off again and this time it did not turn off even after the engine had started, so I had to take out the fuse.
I then realised that the previous owner took the fuse out and left it in the golve box!!!
I bought it off a dealer and will goback to him but first I want to know what could be the cause of this?
Faulty wiring possibly? faulty horn or probs with the steering wheel?
Any ideas will be helpful
Many thanks in advance

doctorbubba010

My 2005 525i is experiencing the same problem, on cold starts mostly. If I love tap the trunk fuse panel a couple times and put the key back in it will shut up. I want my horn but I don't want to get in the car everyday and deal with this.
edit: Pulled out the fuse 28 and turned it upside down put it in, and no problems.