[Renee]

Hmm, I handled it different without a hack.

I have an 3.5.1 and an old 3.5.0

I have take from 3.5.0 the reputation.php and overwritten it with the reputation.php from 3.5.1
In /clientscript/vbulletin_global.js I add before

/**
* Opens a window to show a list of posters in a thread (misc.php?do=whoposted)

this:

/**
* Opens the reputation window
*
* @param	integer	Post ID
*
* @return	boolean	false;
*/
function reputation(postid)
{
	return openWindow(
		'reputation.php?' + SESSIONURL + 'p=' + postid,
		400, 241, 'Reputation'
	);
}

In the template postbit_legacy I changed this:

<if condition="$show['reputationlink']"><a href="reputation.php?$session[sessionurl]p=$post[postid]" rel="nofollow"><img class="inlineimg" src="$stylevar[imgdir_button]/reputation.gif" border="0" alt="<phrase 1="$post[username]">$vbphrase[add_to_xs_reputation]</phrase>" /></a></if>

into this:

<if condition="$show['reputationlink']"><a href="#" onclick="reputation($post[postid]); return false;"><img class="inlineimg" src="$stylevar[imgdir_button]/reputation.gif" border="0" alt="<phrase 1="$post[username]">$vbphrase[add_to_xs_reputation]</phrase>" /></a></if>

Also I reset these templates back to the 3.5.0 templates.

1. reputation
2. reputationbit
3. reputation_yourpost

After then the reputation popup works for me for 3.5.1
It's not nice, but it works

I think vBulletin use this new system because many people havn't enable JavaScript.