This WAS working properly, I have an intitialization routine that messes with the tab definition repository and sets up our sites tabs based on a constant class that holds all the tab names.
I used to have one project for our site, we'll call it ProjectWeb - The intitialization routine was here for the tabs, and the page type and block type definitions were here as well. Recently, I changed the code base a little and added another class library project, we'll call it ProjectCore - now this new core project contains all the initilization routines for episerver and the block/page data classes, controllers for mvc, etc. Basically anything that can be compiled. This is working great and has increased mantainability and findability for our code.
The issue i'm running into now is that upon build (sometimes, not always) when the sync routine runs (episerver's standard syncing it does with page/block types to the db etc) the groupname definition for properties gets defaulted to the Content Tab and doesn't actually use what i've defined in my code on the attribute. The only way to get them to reset to the code value, is to hit revert to default on each property setting in each page/block type. I've created a utility to do this automatically, but, I know this shouldn't be happening anyway, why are these values getting ignored?