Slow Performance Weeks after Encryption

I encrypted my organization's laptops several weeks ago and did not return them to users until after I could tell by device performance that the bulk encrypting task had completed. I have two users that are experiencing extremely slow performance on their systems. When the users are typing anything like a Word document, upon each keystroke they see the Windows 7 "circle" icon at the mouse cursor. This seems to come and go several times over the week, and every few days we are getting a request to resolve the issue but after restarting the behavior may not act up anymore.

I found a TID suggesting to change HKLM\SOFTWARE\Novell-FDE\Parameters\ThrottleEncryption to a lower level like Idle or BelowNormal. Is there anything else that I should also try? Thanks!