execute permissions aspnet sql server 2005

Ive created a DAL called Artist.xsd. Ive used stored procedures to access the data. The wizard created a stored procedure called 'dbo.ArtistSelectCommand' Ive granted the ASPNET account execute permissions on this stored procedure When I run the application and try to execute the stored proc, I get this error

EXECUTE permission denied on object 'ArtistSelectCommand', database 'EBSNet', owner 'dbo'.

as far as im aware ive givne the ASPNET account the correct permissions

EXEC

sp_grantlogin [MachineName\ASPNET]

EXEC

sp_grantdbaccess [MachineName\ASPNET], [ASPNET]

** Ive also done this by selecting the stored proc in sql server 2005 and setting permissions by right clicking and selecting properties.

Is there anything else I need to do ?

Try this:

GRANT EXEC on <storedproc> TO <machinename\user>