If you still are having this issue you can try using the desktop software located at the link provided to try setup with the unit.
It's will bring you to an article if you click: I have an older Slingbox or older computer and need to download the legacy SlingPlayer desktop software.
It will bring a dropdown and you just then need to click the here highlighted next to operating system you use.
Sling Media Technical Support
I recently purchased a Slingbox Pro HD and I have attempted to go through the setup process using a MAC running OS 10. As other people it freezes as 25%. Please could you give some details on how I can use the product. At the moment it's a worthless box with some red lights.
Would appreciate if you could contact.