Steve told ya to ask here?
sounds like a bug to me, so vb.com would have been right as you post first
i don't really know the arabic name system, but maybe the problem is because of the strtolower function in user.php
try to open admin/user.php
find this
Code:
" AND INSTR(LCASE(username),'".addslashes(strtolower(htmlspecialchars($ausername)))."')>0"
and replace it with this (code from memberlist.php)
Code:
" AND username LIKE '%".addslashes(htmlspecialchars($ausername))."%' "