This happened to me yesterday. I was able to get on all servers but my main (Freedom). I got on Virtue, sent a petition, and tech support contacted me via email quite quickly. They told me to run a GameAdvisor diagnostic and send them the results. From these results they told me that I needed to have some TC ports open. The thing is - I didn't do anything that they told me to do other than run the diagnostic and send the results. A few hours later I was able to log on to Freedom.
Hope this helps...