RDLC reporting with parameters

I have a parameter in a RDLC report named "allocated_jobs"

There are no Available Values assigned.
It has 1 Specify Values: RTrim(Allocated = "True")

ie; Only rows with field name Allocated and it's contents equal "True" are to be in the report.

Me.JobsDataReportViewer.LocalReport.ReportEmbeddedResource = "Data_Reporting.JobsList.rdlc"
*Data_Reporting is the stored report path in my.settings*

Dim param_allocatedjobs As New ReportParameter("allocated_jobs")
Dim reportparameters() As ReportParameter = {param_allocatedjobs}

Me.JobsAppTableAdapter.Fill(Me.ReportJobsDbDs.JobsApp)

Me.JobsDataReportViewer.LocalReport.SetParameters(reportparameters)

Me.JobsDataReportViewer.RefreshReport()   

The report runs fine, no errors, but without the desired return of the parameter.

All help welcome, thankyou.

Shane.