Hi Logan,
I find that most of the people having issues with 8.1 are people that updated project files midway through the project. This should never be done, particularly with large, complex project files: feature films, multi-camera sequences, documentaries with lots of varying source media, etc. When I was an instructor, I made sure all my students were well aware of this important issue.
I always ask people to try a new project with newly ingested media and projects work as expected in most cases. As astounding as that sounds, the "bugs" customers are complaining about on this thread (and others) cannot be duplicated in house, so we cannot fix that which we cannot recreate. We have even worked directly with some of these customers in trying to resolve these issues to no avail.
That is why it is important for all on this thread to please file a bug report: http://adobe.ly/ReportBug We need more info from you to solve issues, especially those not related to updating a project file.
Updates are always coming up with the Creative Cloud model. I wouldn't expect any fixes related to anomalies introduced by updating a project file. You simply should protect your current project file at all costs. Part of that process is to avoid updating Premiere Pro until a project is complete.
Hope this puts things into a bit better perspective.
Thanks,
Kevin