programme not responding causes system problems

hi, i have a brand new laptop (7 dyas old) it is a asus, 2 gig ram, 1.9 amd
duel . . . came with latest vista.. i am having a problem wich is becomming
more and more regular. i will be using a programme or as i start up a
programe the programme will not repond and need to be closed. However even
though the programme has disappeared it still remains running in windows task
manager. i cannot remove it from there by ending the task again. The two
worst have been adobe premier pro and firefox. The system does not freeze and
i can continue to run as normal however when i try to restart or shut down i
have no response. Occasionally the shut down screen will appear and then not
close. I have to manually hold down the power button to re-boot.

Does any one know what this could be? and why is it only on specific
programmes?

Thankyou all.