TADOStoredProc object problem

[ByzantianX]

I'm using TADOStoredProc object for retrieving data from an Access parametrized query. Everything works fine unless I modify the values of parameters, then, I'm getting the very same recordset as it was in the first execution. The code looks like this:
StoredProcedure.close;
StoredProcedure.Parameters.ParamValues['prm1']:=somevalue;
StoredProcedure.Parameters.ParamValues['prm2']:=somevalue2;
StoredProcedure.open;
//then the rest of the code
....
StoredProcedure.close;

I guess it could be something with caching the data in recordset object of my stored procedure but I really can not figure it out what's wrong. Please, help!
Thank you!