Answers missing and other issues

Hi, I’m using your plugin and I’ve experiencing some issues that are greatly affecting a poll that is open:

– The answers added by the users are disappearing randomly,
– the Poll end date becomes 1-1-1970 also randomly, so the users find the poll closed and are unable to vote.

I need to fix it as soon as possible. Do you have any idea why these things are happening?

Thanks.

The page I need help with: [log in to see the link]