This is a bit spoilery so don't read on if you're not past act 3 and care about surprises.
I'm currently trying to complete the quest 'Alduin's Bane'. I've retrieved the Elder Scroll, visited my buddy in the mountain and initiated the time warp. I watch the three guys kill the first dragon then we all sit and wait for Alduin to turn up so I can learn the dragonrend shout but he never does! I've left the game running for over an hour, the NPCs just stand 'in combat' and 4 lesser looking dragons permanently fly around the top of the mountain. I have reloaded from previoud saves, re-opened the game etc but the quest is just totally bugged and I cant continue past it.
Any suggestions?
Thanks