Well....good news now. I read the an above post about that extra content to download from Marketplace for Bioshock. I did that download, went into the game, loaded from my final save on Proving Grounds (right before I went up to Fontaine) and went into OPTIONS and then disabled the Vita Chambers. Saved it one more time, went up, whipped Fontaine, and then I got the achievement.
Weird how you need to either Download that extra content, or turn off the Vita Chambers in the menu (which wasnt an option for me until I downloaded that content) and THEN it works.
Well either way, just got my 1100/1100 so I'm happy again.