We just released new firmware (sometimes called Slingbox Software) for owners of the Slingbox PRO-HD. This is a cloud-based update, so your PRO-HD should get it automagically, but you can also use Setup on Slingbox.com to check for updates.
How do I know if I have the new firmware on my Slingbox?
Just go to Watch on Slingbox.com and click on Options. Your firmware version should be listed there as 2.1.330.