It seemed really simple reading the notes,
I need to create a report containing a sub report and i need both parts to be filtered for a date range.
I have entered two parameters in the report, remarkably called Date1 and Date2, i have then created the sub report and i have also created two parameters, shock horror, called Date1 and Date2.
In the report i have inserted a sub report box to which i have right clicked and linked the subreport, and then set the parameters to be Date1 =createdon and Date2 also equal to createdon.
If i don't try and filter the sub report then, apart from bringing back all the data the report as a whole works, now as soon as i try and insert the filter into the subreport the report as a whole no longer works, the main report still functions but the sub report section comes back with no data as a message.

