On Thu, 15 Oct 2009 11:30:20 -0700 (PDT), RicodJour
wrote:

You're dicking around with trying to improve something that is
substandard. Don't. Bite the bullet and just put down a 3/4"
subfloor on top of what you've got, then it doesn't matter what you've
got and you don't have to worry about attaching the layers. The price
difference is small and the savings in not having to mess around with
underlayment nails and worrying about attaching two layers is
obviously worth it.

LOL!