I have had this problem for awhile now.
Whenever I try to open a PDF document on my compuuter Adobe Reader opens it, but when I go to scroll or click on one of the tabs I get (Not Responding) in the title bar. I wait for a short time but it just hangs, and when I click anywhere in the window it goes opaque leaving only the red X cancel button clear.
I was running the latest version of Reader, but uninstalled it and installed an earlier version (9.4) thinking it might fix things, but still getting the same problem.
My system details: Win7 Home Premium 64-bit OS