The second gen HD DVD players put out by Toshiba will not upconvert to 1080i with only a DVI input. Believe me, even though I currently own two HDTVs with only DVI inputs, I now have to purchase a newer HDTV rear projection TV that has the HDMI inputs, and I need two.
Newer technology can be a little tricky sometimes and very expensive to learn.
It appears the inability to go from HDMI to DVI was specifically placed into the player by Toshiba. That's unfortunate, because Sony didn't do the same with the PS3. HDMI to DVI works fine on that hardware.