Sub report won't render lookup data fields

[Durbslaw]

Hi Group,

I have 2 RDLs, the second is a hyperlink that exports to PDF from the first, each report renders and export to PDF fine, however when I click on the hyperlink to render the second to PDF the lookup data comes up as empty fields

I am using the

=Lookup(Fields!Con.Value, Fields!CON.Value, Fields!VAT.Value, "qVatRate")

notation.

Any help will be appreciated.

Regards