Try deleting the "Ironclad Games" folder. Its got a new location different from Sins Trinity. C:\Users\"Your User Name"\My Documents\My Games\Ironclad Games

"Your User Name" is the name you use to log into windows.

Back up any Save games, Screenshots, and Mods before you do this.

What this will do is remove any and all old leftover beta files. Giving the user settings a clean slate. Restart Rebellion, and it will automatically create a new Ironclad Games folder, and subfolders.