I too am having a problem like this.
My xbox is connected to the roxio via HDMI - HDMI cable, and the monitor is hooked up via HDMI (in the roxio) - DVI (on the monitor).
I can see the xbox dashboard on my roxio program on my PC but I have nothing coming on my monitor. The source is correct on the monitor also..
When the xbox is connected directly to the monitor it is via the HDMI - DVI cord and it works perfectly fine.
Someone please have an answer for me as this is very frustrating...