Anyone had this happen.

I opened the boot this morning, key was in my pocket, and the alarm went off. Pushing buttons on the key fob wouldn't do anything.  Alarm stopped after about 20 seconds, but then sounded again a few seconds later.  I could also open the drivers door, again using the keyless method and not pressing any buttons.  Tried to start the car but got the "key not detected" message.  So the door locks were obviously seeing the key, but the alarm and engine start were not.  Got the spare key from the house and all worked normally.  Could lock the car and unlock (again keyless method with key in pocket).

Dealer suggests it may be the battery in the key fob, but I'm not convinced as the doors were working fine, surely with low battery they wouldn't work.

Anyone got any ideas?

It might just do if your body was shielding the key fob anyway it's a cheap enough fix to try.

Yeah I'm with the battery guy on this one. Once it gets marginal all sorts of weird **** happens. !