While I could not find the solution to my problem, it solved itself. I am not certain, but I think it was this code snippet that made it work.

self.dbmanip = CoreDB(self.userTableView, self.table)

This was put inside of the SetupUi() method created by the Qt4 Designer. I think either the dbmanip that contained the TableView lost the information from the proxyModel, or (more likely), I may have referenced the wrong table between the proxyModel and the original Model (that created the proxyModel), and then couldn't display because it was calling the cell structure from one table and the actual information from another.

These are all guesses though. Still, problem solved.