I've come across two occasions when a cutscene simply stops playing with Windower loaded; the game doesn't freeze, on-screen animations still play but it appears that the scripted camera moves simply stop.
I've seen mention of this problem in a couple of FFXIEncyc. quest guides.
The CS play fine when I don't use Windower .. and I can play the same CS WITH Windower on a second PC without an problems.
From the Wiki comments it's obviously a 'known' problem, is there anything that can be done to fix it?