I tried to move the
$spacer_open part to the navbar to get the wifth of the header for the navbar, but this little mod doesn't work with the USC 2.2 - I changed the parts in the xml wich says:
$vbulletin->templatecache['header'] = $vbulletin->templatecache['header'] . '";$spacer_open="';
to:
$vbulletin->templatecache['navbar'] = $vbulletin->templatecache['navbar'] . '";$spacer_open="';
and it seems to work.
I don't think, that you can change your mod to do this automagically, but I wanted to mention it, since it gave me a big headache.