Copying Forms

I may have found the glitch that is causing the problem. It won't allow me to copy a form unless I open it first. On the main forms page, clicking the menu icon in the upper-right hand corner of a form gives the copy option. This was resulting in an error and session-id code. If I click on the form to open it, then go back and try to copy the form it works just fine. I can even copy forms that already had responses.