Premiere has adjusted PAR settings to a more precise number starting with CS4, which adds those bars on the side when exporting to non square pixels. That’s really the only way to not stretch your footage in the conversion process.
They do fall within the production frame, and would not be displayed on a TV, but they do show up on computer playback.
The solution is to crop your footage in the export window, 8 px for top and 8 px for bottom.
Vince Becquiot
Kaptis Studios
San Francisco – Bay Area