Appreciate the reply but that issue seems to be different. I understand they can render different, that's fine.
However, this issue we are dealing with is our TextField's aren't just rendering different they are completely off by a factor of 10-15 pixels or more. This is a huge deal when trying to make UI that lines up cross-platform (which, ironically, is one of the biggest reasons to use Flash)
I accepted that it might be an issue during publish time since they are embedded fonts and thus use the OS' font rendering algorithm when publishing. However, as mentioned in the original post creating a new FLA and setting up TextField's the same exact way produced the desired result.
So this is obviously a bug of some kind with Flash in the way the .FLA is setup or being published. Something is causing them to be off that shouldn't be because this isn't 100% reproducible by using the same steps in a new FLA.