The Date and DateTime fields in MySQL tables are stored like characters, e.g. date is stored as "2006-08-02". When cursoradapter retrieves empty dates, it gets changed to NULL. I had a similar issue a few days ago. The date field in MySQL table was empty (shown as "0000-00-00" in MySQL table). When I put the current date (Date()) in the cursoradapter's cursor and ask it to update the remote data, the command would fail. As a quick workaround, I avoided empty dates in MySQL table.

You may like to have a look at the command the cursoradapter send to have better understanding of the problem.