I also find that the problem affects anything that tries to use the Browse functionality, /content/browse
It seems my custom sitename_admin siteaccess is at least in part to blame as switching back to corporate_admin restores the desired functionality.
It seems the SiteDesign site.ini.append.php setting was at least in part able to solve it. I switched from SiteDesign=custom-design-admin back to SiteDesign=admin. This restored my previous functionality by reverting the SiteDesign.
I'll have a gander at the differences of the two site designs, there should have been none as they were supposed to be the same. Possible permissions problem?
Anyway, I figure this is the second time I've encountered this negative `my custom configuration functionality`, I would share the experience.
