IPad 2 won't connect to home Wi-Fi (but other iOS devices and laptop are connecting fine)?

I have successfully connected my laptop, iPhone 4, AND iPod Touch (2nd gen) to our home Wi-Fi, but my iPad 2 won't connect. It keeps saying that my password is incorrect. Well, it was correct for all my other devices! I haven't made a typo or anything like that because I have re-tried at least a dozen times, very carefully, and it still says the password is wrong even though it was correct a few minutes ago when I set up my iPod Touch for the first time.

Any ideas? Are iPads more susceptible to this kind of thing?

If the password is correct and all that, make sure that you are connecting to the right AP.
Make sure Check the iPad settings to see that everything is correct.
Check the iPad settings to see if you are using DHCP.

Check in the Wi-Fi router settings that you have not accidentally blocked the MAC address of the iPad.

Someone could have changed the password, edit your router and find it or ask if anyone has.
OR you are running an incompatible type of security for the iPad like WEP ( I doubt that it would be WEP )