Error insert/update to sybase iq using sap data services

Hi all,

I have a Job:

In my script:

If my data flow is null, i execute job.

Result:  table target DP_AC has data (data row: 99999,1,a,a);

(table DP_AC in SYBASE IQ).

Then, I add transform in data flow:

In my Query:

The next, I delete data in table DP_AC, execute again Job.

Result of data services is error:

DBS-070407: SQL submitted to database <> resulted in error <> Cannot insert or update Column <> : set option 'identity_insert' to the specific table name containing the identity column to be modified.

I set   "SET TEMPORARY OPTION IDENTITY_INSERT = \'sor.dp_ac\'" in my script, why error is identity_insert.

Help me. Thanks all.