I would try them in order:
1) check the database, then check the new parameter
2) verify, using sql server management studio, that the parameter really exists.
3) close the crystal reports and reopen and check the database, then check the new parameter
4) closed crystal reports delete the data source, add the data source back and open the crystal again and check the database, then check the new parameter
5) reboot and then try # 3
source share