In our experience, this type of problem is typically related to a problem with the file you are trying to upload. The most frequest problem is you have selected 'comma-delimited' as your delimiter, and one of the fields in your database file has commas in it. For example: The list you're uploading contains a 'Company Name' field, and somebody enters 'My Company, Inc.' The comma between Company and Inc is breaking this field up into a new entry, which can cause innaccuracies in your list upload report. We also suggest that you place the email column of the list you will be uploading in the last column space. Lists that have the email column as the first column, and occasional empty fields in some of the other columns can sometimes experience missing entries when uploaded. Placing the email column last prevents this from happening.