Should I deinterlace with dvd-rebuilder?

[zavar]

I've never used the deinterlace option with my dvd-backups. Would it produce a better picture if I did?

Also how do I make sure that a movie is actually interlaced?

[MaxT]

You should not. Leave it to DVDRB.
And read this thread (http://forum.doom9.org/showthread.php?s=&threadid=89667) :)