This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori 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.