The error is usally caused by errors at their end, and is not something VG can fix. The normal is that 2 sites works, so if you had all 3 sites working you've been lucky so far.
Also, make sure to install the game under e.g. C:\Games\Wow ... - not C:\Program Files (x86)\WoW ... since Windows have a nasty habbit of changing file permissions under Program Files during updates.