Hi Adrian,
Not that good on report and there may be a better way of doing but this works for me.
Add a text box into the detail section of the report call it "recordcount"
Control source =count([fieldtocount])
'Replace fieldtocount with the name of a field in your report.
Add a text box into the Page footer section of the report
Control source = [Recordcount]
Once you have checked it you can set the "recordcount" Visible to no
Garry