It is sometimes so busy that you get the message, but sometimes it seems to be a browser problem.
When my Firefox updated, something happened that makes me get a busy message all the time on the DIS Boards.
I switched to Safari (I have a Mac) and the 'busy' message went away. So, I am just DISing on Safari right now.
This happens to me each time Firefox updates. After a few weeks, it usually works again.