The error is not a CR error but an ADO.net error. To troubleshoot this and these are things you may have done....
If these works in test but not production, make sure the execute permissions for the user have been granted. I have failed to GRANT permissons more times than I care to admit.
A second thing to look at is if you are using a .Net dataobject. Search your project code for the name of the test server. I had a similar problem and found that while I was changing the connection string in one location there were other locations that held test server connections and not production.
I would test the stored procedure by trying the value from drop down box that is raising the error. You do this by executing the stored proc and then passing the parameters, depending of database. You may be require to hand code the values and then execute the sp.
I would hard code the parameter values in the report selection formula to make certain they work there.
If it checks out I make certain that the data typing is correct. I have never written a CR parameter to pass through to a database parameter, but I suspect that CR having fewer datatypes creates room for errors.
Finally, I would step through the code to make certain everything passed is as expected. You may want to create a few objects to read the values as they being passed to be sure they are what you want.
Maybe there is something here that will help isolate the problem.
Regards
John W.