Erro ao publicar pagina com datalist

Galera, tenho uma pagina onde inseri um datalist em vb.net

Ao publicar, no navegador aparece a seguinte mensagem de erro:

Server Error in '/Workbook_teste' Application. 

Both DataSource and DataSourceID are defined on 'myDataList'. Remove one definition.

Description: An unhandled exception occurred during the execution of the current web request. Please review the

stack trace for more information about the error and where it originated in the code.

Exception Details: System.InvalidOperationException: Both DataSource and DataSourceID are defined on 'myDataList'.

Remove one definition.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the

origin and location of the exception can be identified using the exception stack trace below.

Por que? :(

Obrigada, Beijão :*