Colin & I were talking this over for our Post of the Week recording, and I realized I had recommended using the wrong single pool -- I have corrected my previous post.
Also wanted to re-iterate that the persistence profile with "Match Across Virtuals" must be applied to both virtual servers ("Match Across Services" might work in your case instead since the VS address is the same)
Will post back with the Post of the Week link when it gets published next week. In the meantime, post back if you have questions.
/deb