only 1000 groups in a parameter? - Crystal Reports

I have set up a report in crystal to review my works orders from sage50man. The crystal report has a the works order number set up as the group and there is a parameter set up to sellect which groups to display. This was working well until we had more than 1000 works orders in sage50man. The parameter field will not see anything past 1000.

Is there a way of getting round this or is it a limitation of Crystal