After many months of procrastination I finally got v4.0.1b running on my DirecTiVo and am listening to an MP3 streamed through HMO right now. This guide is pure gold. Just about the only thing it covers is actually getting v4 up and running properly on your DirecTivo. It worked and only took about 1 hour.

PS- RID stands for Receiver ID and was aparently a measure taken in newer DirecTivo models to prevent successful installation of v4. The only DirectTivos that are non-RID are aparently the original Hughes HDVR2, DVR39, and Philips DSR7000. The box I tested on was a Hughes DVR80 (which is RID). Works like a charm.

There are some new DirecTivo boxen out in the channel now called R10 which are DirecTV-branded and unhackable at this point.