My original Installshield Windows Installer project had a package code of
{3E20494E-F1C8-4CC5-A6A6-FC0A8340F53E} in the "General Information" screen.
I installed the package.

Now I want to create a quickpatch, so I use the quickpatch wizard to point to the original MSI of the installed package.
Once I do this however, the package code it is pointing to is
{6F5A5077-903E-42D6-8C23-D7124B58B53F} according to the ISQuickPatchProperty in the Direct Editor user interface of the QuickPatch development environment.
Why is this Package code different to the one in "General Information" of the original install project? After all I am pointing to the uncompressed MSI of the original project.