Nginx reverse proxy Apache with W3 Total Cache Xcache blank page

First off, I will explain the issue to you. As I’m a developer, this is an embarrassing question, but I’m at a loss.

I am using Nginx as a reverse proxy to Apache2, with mysql-server-5.1 & php5. I’m using WordPress 3.0.1 with W3 Total Cache, and I have Xcache installed. However, when I activate Xcache as the cache method for W3TC, anytime I try and perform an action or navigate to a page that has a query string at the end of the URL, I get the white screen of death.

I was wondering if any of you have had this problem, as well and if you found a fix?

Thank you!