In case anyone else needs the answer, I did get to the bottom of it.
In the RPCL folder in the H5B installation directory, there is a file called 'smartytemplate.inc.php'. This file is adding the extra div wrappers around every referenced component.
To stop it, search the file for '_outer' and you will fine 2 sections where the extra divs are created:
if ($v->inheritsFrom('Control'))
{
if ($v->DivWrap) $code="<div id=\"".$v->Name."_outer\" style=\"display:inline;$style\">".$code."</div>";
}
else $code="<div id=\"".$v->Name."_outer\" style=\"display:inline;$style\">".$code."</div>";
You can just comment out this section of code, and the annoying wrappers will go away.
Hope that this is helpful!