Okay, here is how I was able to reproduce this bug:
1. Create a new task on OF Mac with start date today, due date today, and recurring every 1 day
2. Sync the OF Mac with Omni Sync Server
3. Sync the OF iPhone with Omni Sync Server
At this point both OF Mac and OF iPhone have the same data.
4. Mark today's occurrence of this task done on OF iPhone. Quit OF iPhone before it syncs.
5. Mark today's occurrence of the same task done on OF Mac. Manually sync OF Mac.
6. Open OF iPhone and sync.
Now there will be 2 occurrences of the new task for tomorrow.
I don't normally manually sync, of course, but I think this demonstrates that something in the sync is not catching or resolving conflicts correctly between steps 4-6.
I hope this helps. I've already sent this to the support ninjas.
1. Create a new task on OF Mac with start date today, due date today, and recurring every 1 day
2. Sync the OF Mac with Omni Sync Server
3. Sync the OF iPhone with Omni Sync Server
At this point both OF Mac and OF iPhone have the same data.
4. Mark today's occurrence of this task done on OF iPhone. Quit OF iPhone before it syncs.
5. Mark today's occurrence of the same task done on OF Mac. Manually sync OF Mac.
6. Open OF iPhone and sync.
Now there will be 2 occurrences of the new task for tomorrow.
I don't normally manually sync, of course, but I think this demonstrates that something in the sync is not catching or resolving conflicts correctly between steps 4-6.
I hope this helps. I've already sent this to the support ninjas.