I noticed that you are not able to update the Slingbox firmware. The issue might be caused by the Ethernet connections that you are using. In case that you have SlingLinks on your network layout try to remove them and update the Slingbox while being hardwired to the router.
This link will show you the steps:
If you are not using SlingLinks, or the issue persists, try to reset the Slingbox and give it a try.
Feel free to use this link as a reference: