I just triggered this problem again. It seems to be related to Google Calendar sync and Android App sync. Here is what happened.
- I had the Android app open, looking at a "Due or Overdue" smart queue I created. My task "Call Steph" was overdue.
- Using Google calendar, I moved the task from yesterday (Tue) to Thurs.
- I went to the app, and the task was still at Tue. I clicked Sync and it was still set for Tue, even after refreshing the Smart Queue.
- I checked the GQueues web interface and the task was correctly moved to Thurs.
- I closed then restarted the app, clicked Sync again, and the task continues to remain set for Tue.