cannot delete records via jdbc

[hrubes]

Hello. When I try to issue a sql command to delete some records, or when I try to call a script using CallableStatement, I get the following error:

java.sql.SQLException: [3] Unavailable Command

I can run queries with no problems on other files, and, most strangely, a query that doesn't return any data runs without an exception on this particular file.

The .fp5 file is running in FM Developer 6.

Thanks in advance for any advice.