SRM Documents and Attachments

I am trying to attach a document to my Shopping Cart. Under the tab Documents and Attachments nothing happens when I select the Search and Add icon. This seems to be a problem with the PC settings. It works on some PC’s in the office but not others. It does not seem to be a security problem, I can sign on as the same users under two different PC's, one works the other does not.

Anyone have any idea what setting is keeping me from attaching documents?