This does not happen with any other online games and has only been happening since (approximately) the beginning of August 2012.
I have been told that this may be due to the constant background download that is going on at the moment.
So, to test this theory, is there any way to turn the background download off ?
... I have tried that (disabling both "download while playing" AND "peer-to-peer) but at the bottom of the launcher it is still marked:
World of Warcraft is up to date
Downloading data for next update
Is that normal ?