Macbook V Wireless network

Hi,

I have an ongoing problem that only occurs on my MacBook Pro, no other device in the house has an issue.

When I open up my MB sometimes I am already connected to the network but more often than not I have to rejoin.

I am asked for a WPA2 code which I enter and the MB tells me repeatedly (up to 20 or 30 times) it is invalid ( which it isn't), I keep pressing JOIN and finally it accepts the password. This varies as sometimes it will accept it within a few attempts.

My question is who is going to win the Superbowl...........no sorry, does anyone know why this happens and if there is a way to stay connected to my home network?

Thanks in anticipation