CS6 auto-size text boxes on master pages

I have been working with CS6 auto-size text frames for 2 days and am already in love. They work so beautifully, but I can't get them to work on my master pages. Does anyone know if the auto-size works with a primary text flow box (wiht threaded text)? Master page text boxes (with threaded text)? I can't seem to find much information about this.

Thanks

Debbie