The following link will provide you with the steps to follow in order to update the Slingbox firmware version.
Just make sure to read all the information and follow the included steps.
My slingbox has quit working on my ipad. Of course it says I need to upgrade the firmware. The problem is that I cannot get a connection from my PC to update the firmware. In the setup screen I am getting the message that it cannot find my slingbox. Even though my wireless extension was working fine, I still went and bought a slinglink today to try to get a better connection. I am still having the same problem.