Not necessarily. Does your DVR have a second set of outputs ? You could plug these into the Slingbox. Although one word of warning, if you use the HDMI connection to the TV, many devices block any other HD output so you would not be able to use the component outputs.
It should also have an SD output you can use for the Slingbox.
But if you really need an HD output to your Slingbox then your solution is possibly the only one.
And the rationale behind not supporting HDMI is quite logical, with the HDCP protection system now being built into most A/V devices it would not make sense.
So, yes I do "really need an HD connection" to my slingbox, because I'll ulitimately be viewing this on an HD projector with an 102" screen. I'll have to try it a few ways. I just don't like being forced to revert to a substandard interface to support a remote access device.
Okay - so I don't want to start a component cable quality v. HDMI quality argument, but HDMI is easier to cable, easier to find and installed a broader array of devices... new devices at least. That's my experience. Why not just go 100% HDMI? It would reduce to footprint of the inputs. You plug it in. It works.
Thanks for the answers.