I am having an issue as well, in the last 2 weeks or so, my slingbox pro hd lost its network connection, I thought it was the network cable, so I tested it with my laptop and it is working fine. I tried resting the slingbox as well, that did not help. Was there an update that was sent our or someting? I have never had this issue before. My network light will flash occasionally, 5 blinks, then a pause, then 2 blinks, another pause and then the slingbox symbol starts its chase sequence.... kinda crazy..
If you have issues getting solid lights on the Slingbox, I recommend to have a look at this link,
Have you tried a different power supply?
Let us know how it works