Very nice, thank you for sharing!
--EDIT--
You've added too much code in your "Replace" instructions, it should just be:
Code:
<table cellpadding="0" cellspacing="1" border="0" width="100%">
<tr>
<if condition="$show['thisfoldertotal']"><td width="$tdwidth[folder]" style="background-image: url(images/pmbars/bar_red.gif); font-size:10px" title="<phrase 1="$totalmessages">$vbphrase[messages_stored_in_folder_x]</phrase>"> </td></if>
<if condition="$show['allfolderstotal']"><td width="$tdwidth[total]" style="background-image: url(images/pmbars/bar_orange.gif); font-size:10px" title="<phrase 1="$bbuserinfo[pmtotal]">$vbphrase[total_messages_in_all_folders_x]</phrase>"> </td></if>
<if condition="$tdwidth[quota] > 0"><td width="$tdwidth[quota]" style="background-image: url(images/pmbars/bar_green.gif); font-size:10px" title="<phrase 1="$permissions[pmquota]">$vbphrase[maximum_allowed_messages_x]</phrase>"> </td></if>
</tr>
</table>