Hello
I’ve tried creating quicktimes from Avid which have failed too. From what I understand, you can not export files which are larger than 2 gig. I got round this by spliting my timeline up into sections (using add edit so you can clearly see the setions) and exporting each chunck. I then plan to import into imovie and put it all back together again to then burn DVD within iLife.
It may seem messy but that’s all I’ve come up with.
Hope it helps
Alison