WotLK I get disconnected a lot

Why do I get disconnected so often? And it's only at some certain times. I can play without any problem in the mornings (EU time) but suddenly at 15.00 or 16.00 I get disconnected and relog back in, then DC'ed again, and relog back in, DC again... that happens in 1 minute like 3-4 times and... the 5th or 6th time that I get disconnected... suddenly THERE IS A QUEUE OF 1.500 PEOPLE!!?? Is that queue real? So, out of the blue, there are 1.500 more people logging in... just by the time I am getting disconnected... I don't understand a thing. This happens to me everyday now.