After you install Security Update 839645, you may experience sharing violations and increased network traffic under Windows XP - After you install Security Update 839645, you may experience one or more of the following: The ToolTip feature may give the same file properties for files that are located on the network as for files that are located on your local computer. You may experience sharing violations if you try to open a file on a network share while another user is using ToolTip with the same file. You may experience an increase in network traffic. (disable tooltips completely)