Trouble using % percent sign in usernames with MySQL auth

Hello, i am running into problems while using usernames which include a percent % sign. The rlm_sql_mysql module apparently translates these into the ascii of "=25". So a username which was isp/somebody%somewhere gets translated into isp/somebody=25somewhere. Additionally these users are listed incorrect via dialup admin. If you click on their names (even if they include the =25) you cant administer them since dialupadmin apparently strips out the equalsign (as well as the percent sign). Is anyone observing similar behaviour and/or knows of a fix? Regards, Jonas