Volvo: Engine RPM and door lock, volvo s60, 2002 volvo s60

Question
I have 2 questions, first, I have a 2002 Volvo S60 non-turbo with 45k and while driving when I step on the gas to increase speed, I sometimes hear a noise as if the gear had slipped and shifted to neutral and then it picks up the gear again. Lastly, sometimes when I lock the car the passenger front door keeps unlocking when I press the lock button on the remote. I have to physically open the door, push the lock pin down and then close the door. Have you heard this before.  

Answer
Lago,
The trans could be starting to slip. I would take it to a Volvo shop for them to test drive and advise further. Have the shop read any codes that might be in the trans control unit. Those codes may leed to a failed part.
Door lock actuators have been failing and the operation of the lock is very eratic.