Captainbob is right on. Absolutely do not install insulation that is faced. This vapor barrier will definatly trap moistue and you'll end up with big problems. Just leave the vermiculite alone and install the unfaced batts ontop inside each cavity. Here's a link that'll explain :
http://www.owenscorning.com/around/i.../faq_attic.asp
And here's another one to help you out with additional info:
http://www.ornl.gov/sci/roofs+walls/...on/ins_12.html
Also, where a respirator that protects against asbestos fibers when installing your new insulation up there in the attic. Not all vermiculite contains asbestos but most does and there's no way of knowing what type you have unless you take a sample to a local lab and get it checked out. It's only dangerous when it becomes airborne so try not to kick it up too much while working up there. Below are a few more websites to give you lots more info about it.
http://www.inspectmichigan.com/watsonsj/May00WJ.htm
http://www.radonpro.com/Vermiculite.htm