1) DVD-R Booktype bits will never be set! because DVD-R does not support bitsetting. The Booktype is pre-embossed on this media in the non-writable part. Bitsetting is a + feature only
2) Check your media. I have a cakebox of DVD-Rs (Verbatim DVD-R 8x MCC02RG20). The first of the Cakebox I wrote work in my laptops DVD-ROM drive without problems. Now about 10 are left and they stopped working in the lapÂ´s DVD-ROM drive. I suspected a hardware error, eide problem, issue with my power supply and so on. Wrote the same data with the DW1620 and the LG GSA-4163B. None of them worked, but both read fine in either the BenQ or the LG ...
It was just the media being worse (or different) somewhere in the same cakebox! So if you want to be sure, get some other quality DVD-R media and retry... or:
My advice is, forget about -R at all if you dont have any device which needs it. Compatibility is not an issue, and DVD+R has many advantages as well. Example: On my laptop with Tosh SD-C2402 DVD-Rs get a transfer rate of 2x average, +Rs about 6x average. And thats a really old drive!