I purchased my Pro-HD in Sept 2011 just days before I left on a 4 month trip to India...everything was set up for remote viewing and I was looking forward to being able to access my cable feed while I was away. When I arrived in India and was able to find a highspeed connection (about a week later) I was unable to connect to my Slingbox. Nothing had changed except I had asked the cable company to relocate install a second cable modem in another part of the house so I could have a VOIP telephone. The modem the Slingbox was hooked up to was not changed.
I jusr returned and tried troubleshooting the system...the system set-up recognized my Slingbox and took me through the set-up...when I got to the Input Config the program scanned my cable connection but reported that it detected no video signal...I did this several times switching from coaxial to composite just to make sure it wasn't a bad wire or port. I saw a post in the Forum referring to a similar problem that was resolved by resetting the Slingbox...I followed the link to the reset information and reset my unit. I went through a new set-up...the device was recognized...the video feed appeared in the screen just to the side where I was asked to allow scanning for channels...I selected the rapid scan...waited while it scanned and was given a "no video detected" message again. I rest the unit and tried again with the same result.
BTW before I tried all of this I update all my Slingbox software.