Using the latest VM (D3D flavor) up to update 4041, I select open from the 
main menu, then file.
I point it at my changes file.
Middle-mouse to read in a changeset of the last 1M characters.
Whenever I put my mouse over the resulting changes log (blue  background) 
the CPU goes to the max.  No clicking is required.  If I move the mouse, 
CPU goes to 0.

Running on Win2K.