As the screenshot shows windows registry is granting read write acces, while qlikview is granting only read access. Windows ODBC log tracer shows the session was opened with a read access to execute scripts.
I am successfully execute the same script in Aginity Workbench with the same login access.
With the same ODBC connection in Qlikview I only manage to view records in the table.
I don't think that's on the qlikview-side because the same worked with MySQL which proved the general working of your approach and AFAIK qlik has no further part as to transfer the sql-statement to the database-driver and to get data back (in case of a select-statement). This meant there must be another reason. Are you sure that there is no write-lock on that table when you tried to write the data?