The solution is simply not to use phpmyadmin for anything, ever. It simply isn't a useful piece of kit.
Take backups and load them using the mysql command line tools - these get it right 100% of the time (or more than phpmyadmin at least).
Only use the proper supported methods for creating and restoring database dumps.
Ensure that your encodings are completely consistent (especially your connection encoding - set it with SET NAMES if in doubt) and it will all work.
Mark