video cd burning

[Leo Frejrud]

hi,

i need help burning video cds.
 some of the MPEG:s i download works perfectly to burn in
toast and later watch on my dvdplayer. but some files, in
various sizes and found at different places, just won´t
work.  this is what toast says when i try to drag and drop
a file in the vcd window:

 "files name" cannot be used to create a Video CD. Please
use the  "video Cd" option in your MPEG
encoder/multiplexer.

what must I do?
thanks, leo