Stored Procedure And VarChar Parameter

I'm having the following (abbreviated) stored procedure:






Code Snippet

CREATE PROCEDURE proc_SomeSmartName @SomeVariable VARCHAR AS
BEGIN SELECT COUNT(ID) AS SomeLabel, SomeField
FROM SomeTable
GROUP BY SomeField
HAVING SomeField = @SomeVariable
END
Now my problem: It doesn't seem to work if I give the @SomeParameter a string to work with, neither via SqlCommandObject nor directly in the Management Studio. The following returns zero rows:






Code Snippet

DECLARE @return_value int
EXEC @return_value = [dbo].[proc_SomeSmartName]
@SomeVariable = 'MyText'
SELECT 'Return Value' = @return_value
Funny enough, when I have the following query, it works perfectly:






Code Snippet

SELECT COUNT(ID) AS SomeLabel, SomeField
FROM SomeTable
GROUP BY SomeField
HAVING SomeField = 'MyText'
Returning one row as it should. SomeField is an NVarChar field, but I tried casting it to VarChar without any benefit, and I also supplied the parameter as NVarChar to test, both without further success. And 'MyText' does exist in the database, in both cases when I run the stored procedure and when I run the SQL statement directly.

What am I doing wrong?