Client can't access sitebuilder.. "Permission denied"

Hi wish to give a subscription client access to site builder... When i access his subscription via admin access, sitebuilder link works fine...
However if accessing via created his user account access ( tried both webmaster and full administrator settings,, same problem) .. when you click on sitebuilder icon it says "Error: Permission denied"

Any one shed light on how to fix?
cheers will