did you update sakray and the anthem patch? Just cause the server's back up doesn't mean you can automatically log on, you have to update first ..
How would I do that?
go to "my computer", then C-drive, and then your Program files folder - you'll find "gravity" and the RO folder inside that - find two things:
your anthempatch (application) and Sakray (also application)
let each one carry out its updates (sakray might take a really long time depending on when the last time was that you updated it)
and you should be able to log in after that =)