bcumby,
try holding the IR blaster in different places all around the box, and not just the front. Look on page two of this thread for the pictures of a place that appeared to work best for that particular TiVo.
If I leave the doors open on that setup it seems to work pretty well for the most part. This is a 540 series TiVo.
When I finally got around to trying to get the 240 series TiVo to work, I found success MUCH easier. I have the transmitter pointing right at the IR sensor on the U-Verse box like common sense would tell you to put it. I have the blaster on the bottom of the box, not the top, and several inches out from the box, but it works great.
So some TiVo models would seem to be easier to get to work than others.
Others in this thread have reported similar situations.
http://forums.tivo.com/pe/action/forums/displaypost?postID=10329017