When you first configure your apple modem, there is a set of instructions that are very anal and direct. If you don't follow them, you will have PC problems connecting, and resetting your apple modem correctly will be a problem.
The password has to be 13 characters for it to work for the PC network.
This may be incredibly rude, but is is very important here.
R
T
F
M
Apple manuals aren't hard, but when they get real pushy about something, like setting up the air port base station, you better pay close attention.