The problem is probably due to your field names being reserved words, and as such should not be used as a field/table name (it confuses the query parser within the database system).

If you change the names (in the database and your code), it is likely to work correctly.

For more information (including lists of Reserved words), see the article What names should I NOT use for tables/fields/views/stored procedures/...? from our Database Development FAQs/Tutorials (at the top of the Database Development forum)