1. TDK media is now godawful junk that fewer and fewer people are finding success with. The other choices out there aren't much better, because all the media brands now subcontract to the same crummy factory that slaps different brand names on the same awful discs. You could wait for Office Depot or Best Buy to have a sale on Verbatim, but even that is sketchy these days when bought in stores: its the 16x speed rating that throws the recorder off. You could buy some 8x rated media online, such as Taiyo Yuden Premium or Verbatim DataLife- these will burn in almost anything, even a failing recorder. You could also try different disc "flavors" and maybe you'll hit one the recorder likes: try +R, +R/W and -R/W as well as the usual -R.
2. Sony is releasing about the worst DVD recorders on the market in the USA right now: nothing but problem reports on all of them. Either they don't burn properly, or they "imagine" ordinary TV shows are copy-protected and stop recording in the middle of a show. Not the best choice. But as with the media itself, recorder pickings are now slim. Unless you're willing to spend a little more for a Panasonic (or better yet a Phillips/Magnavox with hard drive). The 2007-2009 Sonys and Toshibas made for the USA are pretty lame, and the off-brands are worse. Since the bottom dropped out of the DVD recorder market in North America a few years ago, mfrs don't sell the "good stuff" here anymore- we don't buy it, so they dump junkers on us. The only ones left that are any good are the Panasonics and Phillips units often recommended by members here- if your Sony eventually dies and can't be fixed, opt for one of those two brands.