I'm in "Completed Task List View" and "By User" is selected. Which user is this? Is is the user created or user owns it  (user the task assigned)? If it is the user who created then I need to see the user name in the view :) so that it helps me. If it is the user the tasked assigned then there is something wrong since it is not sorted by that user :(

Please refer to screen shot attached for details.

-Jale