PC connects to router but Mac Airport will not

Here is the hardware and software specs:

Dell laptop running Windows XP
iMac running OS X 10.4.11
Netgear Wireless N-150 WNR1000 Router

I set up the wireless network using a PC running Vista and everything set up properly. I then connected to the wireless router using my PC described above and the security was WPA Personal (TKIP). I had to configure my PC to connect and everything is working properly. I can connect to the internet wirelessly with both PCs.

When I try to connect to that same wireless network using my iMac, I keep getting the message "The password you entered is not correct for the AirPort network "XXXXXXXXXXXXX" I am trying to connect to the same network that the PCs are connected to and using the exact same password. Why would it tell me the password is incorrect?

Do I need to tell my Mac that I am not connecting to an Airport station? Someone has mentioned that I need to dig and find a really long password that Mac creates for a non-OSX system.

First thing to try is to turn security off, temporarily, to be sure you can connect at all.

If that works try a WPA key like 123456 or ABCDEF just to keep it simple.

If both those tests work there must be something unusual that your Mac doesn't like in your original password or you're unknowingly mis-typing it. If so try and pick a new password and try again.

Post back with what happens.