Well you should open your board so that we can take a look.
Check if the image file is on the server!
Check your
postbit_rep_button template for similar code
<a href="javascript:MyBB.reputation({$post['uid']},{$post['pid']});"><img src="{$theme['imglangdir']}/postbit_reputation.gif" alt="{$lang->postbit_reputation_add}" title="{$lang->postbit_reputation_add}" /></a>
It isnt!
the code is placed there but image file isnt present.
post here your postbit_rep_button code or replace it with the one above
Looks like D666 is here so he will help you sorry bro
As I have said please open your board so that we can take a look if the image is on the server or you have some kind of template issue!!!