-11037 Serialization Failure

I am intermittently receiving this error inserting single records in my database. I use a windows VBA app to build the insert SQL string and execute it using the ODBC drivers from SDK 2.81 TC3. Database is 9.4UC5 on HPUX11. The description of the error hasn't been very helpful on tracking down what is causing it: --- Serialization failure. This IBM Informix CLI error code is the same as SQLSTATE value 40001. The following functions can return this error code: SQLExecDirect(), SQLExecute(), SQLExtendedFetch(), and SQLFetch(). IBM Informix CLI terminated the transaction to prevent deadlock. If you consistently receive this error, a problem exists with the logic in your application. --- I am at a loss trying to figure out what is causing it as it doesn't occur every time. The table I am inserting into has a char(1),int primary key with no serial fields. Any thoughts or ideas welcome. Thanks, Randy