97 740il alarm issues

Anyone lock up the vehicle and for no reason that is obvious, the alarm system goes off about 5 mins later?

Hints?

Are all your doors securely shut? Check all windows to see if they're all up.

I just went to garage. Made sure all windows were up, doors closed. Set alarm and exactly 5 mins later, it went off.

maybe theres something rong with teh anti-theft sensors

Does anyone know how to keep the interior monitor sensor from being active? I drive with my pet and want to lock the doors when I go into a store and the alarm goes off. I don't have a 96, 740il manual so I don't know how to do this. I'll even shut the entire alarm off is it's necessary. Help appreciated.
Dan