Report problem / views on Leads

Report problem / views on Leads

I am using Zoho CRM for responding to web enquiries. As a result a key view is to list all the Web Download enquiries that have not yet been responded to, in order that we can email them individually or in bulk.
I just can't get this view to filter any results. I have set it up as uncontacted registrations and filter for those that have not been set the Lead status of Been sent email. But it does not filter the results correctly. Can you help? thanks