Have you tried to contact the ancestry support about this? I doubt that it will help because many users have this issue with version 2 (and also version 3 I've heard) but maybe they can fix this issue for you. Please post a message here when you receive a useful answer from the ancestry support (I stopped using the FTM software but maybe it will help others).
I think that it won't have anything to do with your setup because you've tried it from two macs over three internet connections. I suspect that something has gone wrong with your online tree and there won't be much you can do to fix this yourself.