That only puts in postbit, what you need to do to put in the profile is this, remember to replace fieldx with the field number you created for their xFire username:
Code:
In MEMBERINFO template find:
<if condition="$vboptions['usereferrer']">
Add above:
<!-- [Xfire Hack ] -->
<if condition="$userinfo['fieldx']">
<fieldset class="fieldset">
<legend>xFire Info</legend>
<div class="fieldset">
<div style="padding:$stylevar[formspacer]px">
<a href="http://profile.xfire.com/$userinfo[fieldx]"><img src="http://miniprofile.xfire.com/$userinfo[fieldx].png" border="0"></a>
</div>
</div>
</fieldset>
</if>
<!-- [end Xfire Hack ] -->