Thank you for posting in the forums! I apologize for the inconvenience of not being able to view the top have of your screen.
This is most likely an issue with the computer you are connecting to the Slingbox from. Have you tried connecting from any other devices? I have seen in other threads that a fix is to update the NVIDIA Driver on your computer.
Below is a link to a thread that proves this to be a resolution:
Hope this helps!
The Sling Moderation Team