I've noticed that whenever the campaign shows high pop or locked for ANY of the alliances (not your own) it becomes impossible to enter Cyrodiil.
The loading screen just sits there until either you get bored or IT does (never the latter). Why is this? Surely the game should be trying to balance the armies by injecting fresh players from the under-represented faction.
'Clever' sigs get old real fast - just like this one.