Does this provide any insight?
I took a look again. I have Verbatim for normal DVD's, but Memorex for the DL disc - sorry about that. That could be contributing to the problem based on what you said, however I've recorded on it before many times with no problem. So could having selected a less than adequate layer break - could that have contributed to the problem?
23:30:08 Using Layer Break LBA: 649343 -> 2056592 (VTS_01, PGC: 1, Chapter: 10, Cell: 10, Vob/Cell ID: 3/10, Time: 00:29:49, SPLIP: Yes -> No)