I have a DirecTV DVR (tivo) and do record to a DVD recorder.
I've had 2 recorders - both Philips. According to
this post at alt.video.dvd on Google Groups, DVD recorders tend to wear out, depending on wear, within a year or two. Which explains why I had TWO recorders.
The DirecTV DVR menu for each show has a Record option - though it sounds like they only imagined recording to tape.
I record to DVD+RWs. I take the DVD+RWs to my computer and suck them in with DVD Decrypter. I use VideoReDo to cut the commercials and break things up into episodes or such. I use TSUNAMI-MPEG DVD Author Pro to create a menu system and produce a set of files that I then use Nero Burning ROM to put on DVD+Rs. And that gives me a DVD that plays like regular ones in all the players in my house, standalone or computer. When played, the DVD starts with the menu I set up (because that's what I've chosen to have it do, you can also choose to have it go straight into playing). I then choose whichever episode I want to watch or play them all.
Short answer... yes you can record stuff from your TIVO box (whether a DirecTV one or not) onto DVDs (RWs or simple Rs) with a DVD recorder.