Locking problem

I am developing a VB application which accesses Informix database and I have the following SQL statement SELECT informix.MasterTable.Field1, Count(informix.DetailTable.Field2) AS CountOfdoc_code, Sum(informix.DetailTable.Field2) AS SumOfenter_qty FROM informix.MasterTable JOIN informix.DetailTable ONinformix.MasterTable.Field1 = informix.DetailTable.Field1 GROUP BY informix.MasterTable.Field1 Having informix.MasterTable.Field2 = '13' ORDER BY informix.MasterTable.Field1 Once in a while I get an ODBC error [Informix][Odbc Informix Driver][Informix]Could not position within a table (informix.MasterTable). It only happens when someone is updating records from a application, but I can get the same records in Crystal Reports, but Crystal Reports retrieves the records and does the sum and count by it self - Crystal Reports does not use SQL statement to get the sum or the count. How can I change the SQL statement so I can get the records from MasterTable and sum and count of records from DetailTable without (what it appears to be) locking the records. Thanks Peter pczurak@bigfoot.com