Well if you need help you can ask myself or the few others here I'm sure. I don't have a PVR350, but I know a fair bit about MythTV in terms of most other things including setting things up from scratch and not from at-rpms. Geographical locations can make a difference too.

Also the MythTV-users list has a pretty low signal to noise ratio (yes bad), so probably best asking here first or direct to me.

Good luck. Trust me, you'll need it.