Post MovableType Migration – All Authors Wrong

So I’m working on a migration of a pretty big blog to WordPress. I’ve run one test import and it worked beautifully including tags and categories – impressive. However, the authors are completely screwed up. I have over 50 authors and few (if any) of the migrated posts are showing the correct author – it seems as if authors have been randomly assigned to the posts, I can’t find any pattern. Anyone have any thoughts on this? Right now, wordpress hasn’t been modified at all, just a totally vanilla template set, no plugins. I could re-run the import if necesary…