Please help, I can't share LB info with co-workers

Folks,
I haven't gotten any help with my problem sharing with a co-worker and I realized that my Subject line might not have conveyed that I was looking for help, so knowledgeable people might not look at the post because they didn't know it was a plea for help.

The original post is at
http://www.llamagraphics.com/drupal/forums/discussion/sharing-projects-c...

Basically, I need two people to really be able to share their ToDo items in LB. That is, there are ToDo items for both people and both people need to be able to both check-off and see what the other person has checked off.

LB exchange files don't seem to work because the Manual says that check-status is not included (though, I pretty sure I saw a checkmark included when I opened an exchange file????) and importing in a ne exchange file just adds all the ToDos to what's already in the file - it doesn't match with ToDos that are already there. Sharing an iCal calendar doesn't work because you can only publish/subscribe and the subscribers cannot change the calendar.

Anyone else have, and solve, this sharing problem?
Thanks, Bonnie