parameter is missing a value

using ReportBuilder 3, I have set up a small test whose solution may then be applied to a larger project.    The report has two parameters;
@ReportNumber;   data type is integer (no checkboxes are checked and it is visible).    
                                  Available values are;     Label                                   Value
                                                                           Report 1                                 1
                                                                           Report 2                                 2
                                                                           Report 3                                 3
                                  Default Value = 1

@ReportTitle:          data type is text ( i have tried all combinations of checkboxes, except 'Allow multiple values, which is always unchecked)
                                  visibility (have tried both Hidden and Internal)
                                  Available Values - (have tried several variations including literal text in the value field "Report Number")
                                                   In the final solution, it will be a a switch statement that will assign a ReportTitle depending upon the @ReportNumber selected.
                                  Default Value - "Default Value"  (for testing purposes)


Every configuration results in "The 'ReportTitle' parameter is missing a value".    

Any help would be much appreciated.

Eric