Ok got it working, sort of. My Charter Cable HD DVR box is not happy with the HDCP on every channel. So, i had to remove the HDMI cable from the slingbox and connect everything using video component cable and the standard LEFT/RIGHT audio cables.
Video appears to come in high def, but i lose the Dolby Digital 5.1 surround sound since i can only use the left/right audio cables. Since this is my home theater setup, not having Dolby Digital surround sound is not satisfactory to me.
Luckily, i have another regular Digital Cable box (non HD) in another room. So, i connected the slingbox to it and everything works again, but i have no HD from that box..
Anybody run into a similar situation and was able to get the HDMI input working on the Slingbox with a HD DVR cable box?