iMessages Login Problem

Hi, i have an iPad, iPhone and a Mac, i bascially want to set up a seperate account so people can send an iMessage staright to my mac without it being automatically sent to my iPad and iPhone, so i created a new hotmail account and a new apple id, however when i try to login on iMessages i get the following. Any help?

I have already activated the account and clicked the activate link when i first signrf up for my new apple id address.

Many Thanks

Ross