When using Mathematica v.3.0 or 3.0.1, Xah Lee reports getting delays of several seconds between pressing Enter or Shift-Return and seeing any response. "No highlight appears on the cell bracket, no disk activity occurs, nothing. After the first delay, further evaluations occur quickly, as expected." Wolfram Research confirmed this adding: "This shows up regardless of the OS version. Our developers are aware of this behavior. It has been traced to the Shared Library Manager extension. Unfortunately, disabling this extension also disables AppleTalk."