I found the check boxof "Prompt if device unused" was grayed out after I setted "Enforce password on device" at Exchange System Manager.EvenIturn off the "Enforce password on device" at Exchange System Manager. I synced my phone but the lock check box (prompt if device is unused) is still grayed out and I have soft reset my phone - but check box is grayed out.Perhaps I'm looking in the wrong place but I can't figure it out. Have anyone knows how torelease it on device?