problem: sometimes when i rip/shrink a dvd, i'll get ready to burn the disc with TMPGENC dvd author, it starts normal, then gets so far, and stops saying, "invalid unit error". what causes this?

I can burn with nero exspress easily an have no problem.
also, this happens at varying %'s, sometimes 1 sometimes 49.

I'm using vesion 1.5.19.59 of dvd author.
I'm also using a nec dvd burner,
I have also done this many times, but lately its been happening more. (2 times in the last week, as opposed to never before.)


does anyone know what causes this?