Thanks for your input everyone. I noticed the problem originally when I opened OM on my laptop first and THEN my desktop.
When I checked I found that I had UNchecked the "keep on the server" box on the laptop but NOT on the desktop.
(I don't know why I didn't realize this ...!!)
So I rechecked the "keep on the server" box on the laptop AND left the box checked on the desktop too...to be deleted after 2 days.
Thanks again for all your help...