You need both a PAL mpeg file and to set the project properties in DVDA to PAL.
However, it is not desirable to recompress your NTSC mpeg to make a PAL version of it. Go back to the original project where you created your NTSC mpeg and render it as PAL instead.
Gary Kleiner
Learn Vegas and DVD Architect
http://www.VegasTrainingAndTools.com