|Image from Crackberry.com
The solution I found is unfortunately slightly typical of RIM in that it's unnecessarily complicated. Here's the solution that worked for me:
1. Rather than going to Email Setup navigate to http://mobile.blackberry.com on your device browser.
2. Select your country from the drop down.
3. Scroll down and select to Email.
4. Scroll down on the next screen and select Integrate Email
5, You will be presented with a screen notifying you that a new device is detected and asking you to move your accounts.
6. You will finally be presented with a screen listing each account and asking for your passwords to validate, enter the passwords one-by-one hitting the validate button on each as you go.
7. Once all accounts are validated you should be presented with a success screen and in 20 minutes your emails will start to arrive again.
I hope this helps anyone else who encounters this rather awkward problem.