If as you say they all have the correctly spelt prefix of the customer's username, at a guess I'd say the only other possibility is the package files are corrupted somehow. Could even be permissions?
Do the packages display for the reseller if you go into the reseller centre edit that reseller then unselect the checkbox that restricts packages to those created by the reseller? Do the packages appear when logged in as root?
If they do, I'd go check the spelling. If not, I'd check the package files. Can you edit and save those packages as the reseller? Can you delete and recreate them?