Ok here is the sollution to work with superclean hs.  Change in file:

supercleanhs /html/gallery.php on rule 29: <div class="rsg_sub_url_single"><?php HTML_RSGALLERY::subGalleryList( $kid->get('id') ); ?>

to: <div class="rsg_sub_url_single"><?php $this->_subGalleryList( $kid ); ?>

Now you got cattegories and the nice supercleanhs working.

something else is the mod_rsg2_scroller_1.0.7 this one conflicts a little with Ijooma magazine when the scroll menu is somewhere else on the site then the RSGallery2 base.

Here is the error:

Fatal error: Cannot redeclare utf8_strlen() (previously declared in domain --->/administrator/components/com_magazine/utf8/mbstring/core.php:26) in domain --->//administrator/components/com_magazine/utf8/mbstring/strlen.php on line 28

I got two places where this file can be found:

administrator/components/com_magazine/utf8/mbstring/core.php and
/components/com_rsgallery2/lib/j15backport/libraries/phputf8/mbstring/core.php

It seems these two are in conflict. When I change the file with each other then the scroller doen not work and then Ijoomla magazine does not work. Both seems to need this core.php but not the same core.php!/version

I hope you'll find a sollution.