I've been tearing my hear out with this problem the last hour, but I "think" I "may" have come up with a working solution.
First install TMPGenc if you don't already have it. Now place this template I created in D:\Program Files\Pegasys Inc\TMPGEnc Plus 2.5\Template\Extra (change to the relevant install Dir!) Right click on the link and select save as:
http://www.marcpeters.co.uk/PAL-to-NTSC.mcf (make sure you change the type from TEXT DOCUMENT to ALL FILES).
Save your movie to PAL DV AVI in Premiere. Now open up TMPGenc. Close down the wizard if it starts. Load your video by clicking the crowse button next to video. Now press load under stream type and browse to the PAL-to-NTSC.mcf you saved earlier. Now click Start.
The preview video may look a bit "ODD", but the final output should look perfect in media player
If this doesn't work, send me a few seconds of you clip (saved as MPEG) to my email address in my profile and I'll create a working template...