Another DVD burning question

[Donald C. Tully]

I am attempting to burn an Imovie 3.0 DVD on my Formac Divideon CD/DVD
burner.  All goes well until I attempt the burn. The recording starts and
then stops after about 30 seconds. The disk is ejected and a message appears
asking that I insert a blank DVD. of course, the original disk is ruined. I
am using Maxell DVD-R disks on an IMac G3 running OS X.2.8.  By the way,
burning music CD's is a snap; no problems...Any thoughts?  Thank You...