Cheers mate. That makes sense as the alarm has been randomly going offBonnet open or faulty sensor maybe, try adjusting the bracket or some other way to make better contact.
The switch is N/C, it opens when the bonnet is closed and the plunger returns to closed circuit when the bonnet is open so if the rubber boot was the problem you should have got the misslock warning all the time... that 1 minute delay with misslock warning after the bonnet was closed is common, happenes to many, not an issue but i couldnt find any 100% logical explanation for it, i suspect that it's because the bonnet monitoring circuit is different than the one for the doors and the BCU needs a short time to calculate the voltage drop on it. I can tell you for sure that the rubber boot is no factor in this behaviour.... the plunger in the switch doesn't return properly straight away. So if I've been under the bonnet, shut it & lock the car immediately the horn sounds once but if I leave it a minute before locking it, all is well.
My son's does this also, if you don't want the horn to sound then cycle the ignition on and off then it resets itself.On mine the rubber boot over the bonnet switch has gone a bit plastic-e due to age & heat under there so the plunger in the switch doesn't return properly straight away. So if I've been under the bonnet, shut it & lock the car immediately the horn sounds once but if I leave it a minute before locking it, all is well. I might try some of that Autoglym rubber reviver stuff to make it more rubbery again.