Yep. The DSO setup that your host has done is probably not going to work. I thought that would probably happen based on your forum topic reply here: http://forum.ait-pro.com/forums/topic/unable-to-install-plugins/page/3/#post-21775.
I will be sending you an email in a few minutes to work with you directly on this issue since it is going to be a very complicated and advanced host server configuration thing to figure out.