Most of the BBS systems are still in "local" encoding. When Coppermine is bridged with these BBS, if the username contains non-ascii characters, it's not displayed correctly in Coppermine. I fixed it with changing USER_NAME into utf8_encode(USER_NAME) in my theme and in themes.inc.php but maybe a better solution would be to fix it directly in the bridge...
By the way, this should be done also for all the profile informations coming from the BBS tables...