It seems that you are having some issues with the SlingPlayer software on your Windows 7 computer.
The fact the the SlingPlayer works fine on your home computer means that the issue is not related to your Slingbox, but your computer. Otherwise, you would get the same behavior on all of your computers. Since that is a work computer, the security software is something to take into account. I recommend you to remove the SlingPlayer software version and reinstall it one more time. Make sure to check this link.