Of the top of my head try the below.  The key is that maExpireDate <
LastEndDate
Select CustomerID, FirstName, LastName, maExpireDate,  
	LastEndDate=(Select Max(EndDate) 
		From Invoices i, InvoiceItems ii
		Where ma.CustomerID = i.CustomerID
		and i.InvoiceID = ii.InvoiceID
		and ii.PaymentID > 0
		and i.Type <> "VOID")