Using a HVR-4400 and windows media center.

I have a 2.4m dish pointed at CS6b to get some chinese channels. I'm using a dual polarization LNB so that the vertical and horizontal signals are on different frequency allowing me to split them to different STBs and have them all watch different channels. This works fine.

When setting up to do the same in media centre, I chose the option to do custom dual oscillator frequency and set them to 5150 and 5750mhz as per the lnb.

First minor issue, cs6b is not on the satellite list so had to just pick another random one and do manual single transponder scans. Is there a way to add new satellites in?

Second issue, it seems I cannot scan the vertical channels as there is no signal. Horizontal channels are fine. But if i select the horizontal setting for the vertical channels and subtract 600mhz from the channel frequency I can get the channels. This seems really hacky to me and was wondering if there is a proper way of doing it.