MacOS – Why doesn’t the new @me.com email address work

The Problem:

I've just updated to OSX 10.7.2, with iCloud support. Everything works fine. Except… when I try to enable 'mail and notes' under iCloud settings, it just gets stuck displaying 'starting'.

If I go to my mail app, I am greeted by the message

Cannot send mail, failed to connect to the iCloud server.

When I try to use mail from iCloud.com, I am greeted by the message

To use iCloud mail, create an @me.com email address by turning on mail in your iCloud settings, using iOS or OSX.

However, I am never prompted to create an @me.com email address when I turn on mail in iCloud settings.

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What might have caused the problem:

A couple of months ago, I reserved my @me.com email address by creating it on my brothers laptop (because he's a developer). In fact, I can even log in to iCloud using this email address.

So basically, some part of Apple's database believes I have an @me.com address, but the mail portion of iCloud doesn't think this is the case and still wants me to create one.

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I'm pretty stuck on this – any ideas or suggestions would be much appreciated.

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Edit:

I had some ideas on a couple of things that might fix it, but don't know where to start on them.

• Do iCloud settings have an associated .plist file? Sometimes
  deleting/modifying .plist files can solve problems. I've had a look
  for one but couldn't seem to find one easily – if there is one, where
  might it be located?

• If anyone else has this issue, what happens when you try using iCloud
  mail from an iPhone/iPad etc?

• Apple support is impossible to contact if you're out of the phone
  support period (I'm still under warranty though). What ways might I
  be able to contact Apple, in case it's an issue with their database?
  Could I file a bug report somewhere, or send an email to some hard to
  find email address?