Thanks for the suggestions. This is what I did to solve:
Suggestion from Claire: I attempted to reinstall the plugins. However, I realized that I was not on the latest 3.1 update center (
www.trgtd.com.au/tr/updates/3.1/updates.xml). I deinstalled the iPhone plug in, connected to the latest update center, and downloaded the latest iPhone plugin.
Result: sync did not work.
Suggestion from S8. I deinstalled the iphone app and reinstalled. Created a new TR file and successfully synced. good.
Then I synced to my old TR file. That successfully synced (i tested various scenarios pushing data back and forth). All seems well.
So maybe it a a combination of the plugin and iphone app?
Thanks for your help....