Have you verified that you're running against the correct database? This is usually defined as a connectionstring property in your component. There may be 2 different versions of the stored proc on different databases.
Another thing to try is to run a trace against the database to see exactly what SQL is being executed by the component.
If worse comes to worse, you can send me a .package and DB build script to richard_wright@symantec.com
Basically, when you generate a SQL component, it will examine the database object and build the code/t-SQL such that it can operate with that object AT THAT POINT IN TIME. If the stored procedure, for example, gets renamed, loses parameters, gets new parameters, your component knows nothing about it. You "regenerate" the component to make it aware of these changes (basically, rebuild the component code). It doesn't delete the old component, just updates it.