Missing Invoices on Invoice Listing

If you want to cross check what is on the Invoice Listing report, you can go to Billing MAnager and filter for the same date range and ask for posted invoices, voided, or unposted invoices and compare them. Keep in mind the Invoice listing report doesn't show you "zero value " invoices - invoices where you have billed out the time at a zero dollar amount. These will appear on the Billing Manager screen, but they are not included on the Invoice Listing report as the Invoice Listing report is going to show you just invoices  where there were billed/invoiced amounts.  Other things to check are your date range and sort order of the report. It could be that the invoice in question is just presented in a different place than you expected based on sort information you are using.