Same problem as reported under #1206022
Once YPOPs! grabs the message, it's gone from Yahoo!
I wasn't able to re-configure to "leave a copy of message
Rolled-back to version 0.70 (from 0.73)
Logged In: YES
This is not a bug. YOu have to tell your email client to
leave emails on server, then it will not be deleted.
ypops doesn't delete emails until the client tells it to.