Lotus group to do

I rely very heavily on the to-do feature to manage my work load and delegate work I have been having an ongoing problem when I assign a group task. When I make a change to the task and hit “save and send assignment”, the assignees are not always getting notified of the change. I have to use the “confirm” button which sends them an email, adds an additional entry under their to do, but does not update the original version of the to do on their computer. The assignees wind up with a new copy of the to-do (placed under the original to do) every time we update the task. Every once in a while it works the way I think it should where the assignee’s original to do entry is updated.