I bought the game (the sequel) from newegg.com for 7.99. I entered the cd key, went on to "register". Which then directed me to the ubi.com to register an account. I select login, and it says invalid cd key.

I have the latest patch too, 1.03.

You're sure you entered the right key?Try it with caps i had the same problem and when i put it in caps (a=A) it worked.
And dont mix up the O and the 0

Ah yeah, i had mistaken I for 1. Thanks alot Orton .

Hey k3ntegra,

Make sure you are entering the key correctly.
I have seen keys entered improperly many times.

It should start with RS6
Also, be sure that you aren't entering an improper character:
Example a letter O for 0 (Zero)

That may not be the problem, but it's a good place to start.

If that doesn't help, you may have to submit a trouble ticket to Ubisoft, supply a receipt and proof of Disk and Box.

Also, I don't know how Newegg's policy is on games, but they have great service on computer components.
I have even had them send me a pre-paid return shipping label for defective products.
It would be worth a call if you can't get it sorted.

Edit:
Thanks for helping Orton,
Your post beat mine in while I was typing.