I’m having the same problem and it started with a new machine running Windows 7 with simultaneous upgrade from Vegas 9 to 10. I notice that Ted is running Vegas 8 which may eliminate my thought that it’s a Vegas 10 issue. My blank discs occur across two different burners and any speed I use. Sometimes they go silent after a couple of seconds and sometimes right at the very end. I have not determined a pattern. Using the pre-render option in the disc-at-once dialog helps sometimes but not always. I have burned thousands of reliable masters using Vegas since version 2 and would love to solve this issue.
Dell Precision T7500
Dual Quad core 2.4 GHz
12GB RAM
Windows 7 x64
OEM DVD burner plus Plextor PX8940SA