I'm sorry to hear about your continue difficulties. As I mentioned in one of my previous replies, we are aware of an issue with the new Auctiva uploader that is causing the behavior you have described to occur for certain Mac users and we are working to implement an update to the uploader that will resolve the issue.
The company we licensed the uploader from has indicated that an update is available that should address the issue and our technical team is working to integrate that update into our site as soon as possible.
Although there are still some unknowns we need to work through at this point, I believe there is a good chance we will be able to get this update in place at some point next week. I'll keep you posted through this thread as any additional information becomes available.