@ Everyone,
You know how everytime you sign into the MS Facebook app it post this "So and So just installed Facebook for Windows Phone" thing on your page. Well, I think I've found a solution in the linked thread. Next time you flash a ROM, try this cab or regedit out before you sign into MS Facebook and let me know if it works for you too. I've tried it 3 times and it seems to work. I've not gotten that automatic post since. Here's the post:
http://forum.ppcgeeks.com/2062346-post6.html
I'll be including this regedit in my ROMs, so this cab or manually entering the edit won't be necessary when flashing any future versions of my ROMs.