I doubt that Spybot has anything to do with since it is no longer on your system. What is the symptoms of the Slingbox itself. There's a network LED, is it either blinking, steady on, or no light? What we're looking for is a stead network LED, this is an indication that it has an IP address.
Something you may want to try is plugging the Slingbox directly to the router. This will reduce the number of things that might cause problems. As a process of elimination, it will help us pinpoint where the problem originates. You can also try a different cable or port.
Another thing that's common, is that the network configuration has changed since you had the Slingbox installed. Like the network IDs changed, or there's a device already using the address which is assigned to the Slingbox. You may want to attempt a factory reset as described on this article (http://support.slingmedia.com/get/KB-1000038). This will wipe out the previous configuration, and allow the Slingbox to accept a brand new DHCP IP address.
Some other issues I've seen are certain firmware / router combinations don't seem to be using the standard DHCP protocol. In this case, the Slingbox tries to get an address but it isn't acknowledged by the DHCP service on the router. In particular, I've seen this most commonly on routers which were replaced by a linux kernel like OpenWRT, DD-WRT, FreeWRT, or Tomato. Usually most cases, a firmware update or reverting to the original manufacturer firmware will usually do the trick.