I understand that you are having some issues with the Slingbox and the attached DVR, since you are not able to control it.
As the first step, I recommend you to connect the Slingbox to a different TV source (cable box, satellite receiver or DVD player) in order to test its functionality. This test will allow you to verify if the issue is related to the Slingbox or to any setting on the DVR. Make sure to follow these indications and let us know how it works for you.
I was able to resolve the issue that I was having by going to the location where my Slingbox Pro was connected and using the internet viewing option while on the same network. I'm not real sure why this resolved the issue, but it did. I can now connect to my Slingbox Pro via internet viewing from an international location and I can control it perfectly all the time.