SSIS Unsupported Data Type on Result Set Binding

[CatchMoreFish]

I am using SQL Server 2005 Integration Service SSIS to retrieve data from
Oracle8i Enterprise Edition Release 8.1.7.3.0 - 64bit Production. One task is
to compare table rows of source table and target table. Following is what I
have done.

1. In BI, I created two variables, SourceTableRowCount and
TargetTableRowCount, both are Int32.
2. In SSIS package, I created a "Execute SQL Task" with settings as:
* Under General
Code Page: 1252
ResultSet: Single row
ConnectionType: OLE DB
Connection: (a connection to oracle server which shared by other tasks
without any problems)
SQLSourceType: Direct input
SQLStatement: SELECT COUNT(*) AS NOROWS FROM *TABLE_NAME*
* Under Result Set
Result Name: NOROWS
Variable Name: User::SourceTableRowCount

When I run this task, I got the error message:
[Execute SQL Task] Error: An error occurred while assigning a value to
variable "SourceTableRowCount":"Unsupported data type on result set binding
NOROWS.".

I tried changing SourceTableRowCount's data type to object, int64, string,
double and none of them worked. I have alos changed the statement to SELECT
TO_NUMBER(COUNT(*)) AS NOROWS FROM *TABLE_NAME*, or SELECT COUNT(*) FROM
*TABLE_NAME*
I got the same error message.

Somehow, I run the same set up on the SQL server side, the SQL task executed
successfully.

Extra Information:
My PC has Windows XP with SP2. Oracle Client 9.02.00.54 Installed. I created
service naming in net manager, then, in ODBC\System DSN, I created a data
source using Oracle ODBC Driver.

Thank you in advance and happy holidays.