Are you using the latest version of premiere elements?
Is it the issue with only Nokia 5700 or with any other cell phone that you play on?
What is the video converted from? And what format is it converted to?
Premiere Elements is technically not a conversion program. It's a video editor. But if you can tell us what type of camcorder your original video came from and what specs you output, that would be helpful.
It also might help to know which version of Premiere Elements you're using.