This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
If this was my problem, the first thing I would do is to see if the blank page is due to an empty reply body - try view source or even better, use the Firefox browser with the Firebug plugin to see what is being returned.
One possibility for a blank page would be failure to flush and close the response stream.