Well, you are both correct.
Domenico - to solve the problem requires setting up a package using ' &userID&_ ' just as it says on the page -- this is in the Server WHM for &Create New Package.& It will still allow Reseller to see any packages created by 'root' though, so keep those to a minimum. For current Resellers you need to create a package in 'root', use their individual account name -- as described above -- then change them over to that plan. Then, and this is the important part, have them create a package for themselves and transfer their Domain Name to it.
ozzi4648 - you are referring to a Reseller providing/creating a &package&, which is true if the &only show this Reseller packages& (or similar wording) within the Reseller Center & Edit Reseller Privileges/Nameservers has been checked. It does not solve the &Upgrade/Downgrade& problem at all.
A lot of people are confused (which is easy to do) between the two types. In fact, the whold issue seems to confusing as even DarkOrb (besides that one-liner they have) does not provide documentation. Hopefully this, and more, will be included in the new Documentation for version 6.0.