Stored Procedure causing log file to blow up

Hey everyone! I am having a n issue with SAP BODS 4.1 and SQL Server 2012. We occasionally need to do a complete reload of some of our source systems into our EDW. We can't truncate the table because there are multiple systems that are loaded. We wrote a stored procedure to delete the EDW based on the source system we are reloading. This allows us to manage the performance of the delete in SQL Server and give us a bit more control over the transactions. The stored procedure deletes in chunks so we can keep the log file clean. Here is the main part of the stored procedure:

WHILE(@RowCount > 0)
  BEGIN
    SET @SQLString = N'DELETE TOP ('+ CAST(@DeletesPerCommit AS VARCHAR(10)) +')
                     FROM ' + @EdwTable + ' WHERE SOURCENUMID = ' + CAST(@SourceNum AS VARCHAR(10))
    BEGIN TRY
      BEGIN TRANSACTION
        EXEC(@SQLString)
        SET @RowCount = @@ROWCOUNT
      COMMIT TRANSACTION
    END TRY
    BEGIN CATCH
      SET @ErrorMessage = ERROR_MESSAGE()
      IF (XACT_STATE()) = -1 ROLLBACK TRANSACTION
      IF (XACT_STATE()) = 1 COMMIT TRANSACTION
      RAISERROR('ERROR: %s',18,-1,@ErrorMessage)
      RETURN -1
    END CATCH
    SET @RecordsDeleted = @RecordsDeleted + @RowCount
    SET @Counter = @RecordsDeleted
    IF(@Counter >= 400000)
      BEGIN
        CHECKPOINT 10
        SET @Counter = 0
      END
  END   

RETURN @RecordsDeleted

When we execute this from SQL Server, everything looks perfect and we are able to see the table count decrease as expected. However, when we call this from BODS, the table count does not decrease and on large table, we eventually fill up the log file. I realize we are executing this script from a single threaded environment, but should that matter? Here is our BODS script that calls the stored procedure:

$V_SP_RETURN  = DS_RD_APMart.DBO.SPDELETERECORDSBYSOURCE(
    upper(substr(workflow_name(),11,(length(workflow_name()) - 17))),
    $G_RDSOURCENUMID ,
    10000,
    $V_AL_SP_RETCODE ,
    $V_AL_SP_ERRMSG );

# The stored procedure will return a -1 if the table passed does
# not exist OR -2 if any of the input parameters are incorrect,
# otherwise it will return the total number of records deleted

# If the stored procedure fails, the SQL Server error
# message will be stored in the $V_AL_SP_ERRMSG variable.

IF($V_AL_SP_RETCODE = 'ACTA_SP_OK' AND $V_SP_RETURN >= 0 )
    #  Successful execution of stored procedure
    #  Print number of deleted records
    print( 'Deleted ' || cast( $V_SP_RETURN, 'varchar(50)') || ' records for '|| upper(substr(workflow_name(),11,(length(workflow_name()) - 17))));
ELSE
  BEGIN
    print( '[workflow_name()] - DS_RD_DWCR.DBO.SPDELETERECORDSBYSOURCE return value: [$V_AL_SP_RETCODE] - '|| cast( $V_SP_RETURN, 'varchar(50)'));
    print( '[workflow_name()] - DS_RD_DWCR.DBO.SPDELETERECORDSBYSOURCE error message: [$V_AL_SP_ERRMSG]');
    raise_exception($V_AL_SP_ERRMSG);
  END

Anyone have any ideas why this blows up the database when called from BODS?

Thanks,

Scott