We are using Exchange 2003 with Outlook 2007 in cached mode. One of my users also logs in via remote desktop to a terminal server. On the terminal server Outlook is not in cached mode.
When she completes a task at her desktop in cached mode and deletes it the task will still show up in terminal services when she is directly connected to Exchange.
I've searched around but it's hard to get through the number of posts of people trying to sync tasks to various devices. I've seen issues where mail or contacts won't sync properly but not tasks. Any everything else is working.