Very strange window problem

[aKiNa2]

I've just purchased a 1998 Boxster about a week ago, its still under warranty for three months but i've found that when i start the engine the windows lower about 10cm...is this normal? Thats fine but when I try to get the windows to go p fully, perhaps one day when it is raining and I don't want the top up, the windows will not go up to the completely closed position.

Sometimes I've found if I open the top and then close it again it sometimes may close fully. Also sometimes when I take the key out and lock it then put the key back in it might close fully

Also its happened where I've taken the key out, with the window being not fully closed and then one window will fully lower but not the other with the key out of the ignition!!!

Sometimes it can be very annoying when I want the window to be closed. Any similar problems? I might have to take it back down and make the dealer deal with the problem.

Thanks

Justin