1. The manual says when you lock the car using the remote, the exterior
That was exactly the problem with my S60 a six months back. The car seemed
locked and the alarm was on. The problem escalated after a month or two,
making the right-hand side door unlock itself right after all the other
doors had been locked. If you opened the failing door the car alarm went
off.
My problem, however, turned up when the car was about three years old, but
was easily fixed by adjusting something concerning the right-hand side door
lock. Volvo charged about 500 SEK (70 USD) for the trouble...