[StarBuG]

ever tried to use the html code for space in that definition?
"& n b s p ;" or "& # 1 6 0 ;" (without the spaces and "!)

like

PHP Code:

if(!preg_match("/^[a-zA-Z_0-9& n b s p ;]+$/", $username)) {
    eval("standarderror(\"Invalid Characters you can only use a-z, 1-9 or an underscore in your username.\");");
    exit;
  } 


(also without spaces of course)

don?t know if it works but it is woth a try

Greetings

StarBuG