Wrong entry wipes all till first entry,

Can't reproduce something like that. Can you give me full path what and how I should reproduce it.
I think that you are talking about not wiping fuel log but the form, right?
If yes - then this is OK. If you are opening add fillup screen - you'll write something and you'll close app, change app. Android could "kill" Fuelio and the form is empty when you are getting back to app. You are talking about something like this?

Not possible that Fuelio will clear your log or something but that the form is cleared - yes. There no such thing as draft. But you gave me some idea about that.

You want probably something like this:
- go to add screen, add odometer

Later you want to add costs info but the odometer info is cleared.

Forgot to tell you. If you think that some item from your log is gone and it was there - check the daily autobackup today.It's located: /sdcard/Fuelio/backup-local/