If you run the Greeting Card Designer on a windows machine, you may have made a change to the Signature.psd file only to find that that change is not displayed when you create a card.
If this is the case, you may find that there are two Signature.psd files loaded on your machine.
The problem stems from Windows changing the common paths between XP and Vista and then using virtual paths to maintain compatibility. At the same time, Adobe Photoshop records only the actual physical path in an action.
For some reason, many Windows machines will create duplicate folders for the Signature file when it's copied onto your system during the installation process.
Fix:
To fix the problem, take a careful look at the path to your Signature File.
The action is specifically looking for the file at...
c:\Users\Public\Documents\Greeting Card Designer V4\Signature\Signature.psd
However Windows will interpret this path as...
c:\Users\Public\Public Documents\Greeting Card Designer V4\Signature\Signature.psd.
You'll find that if you carefully look for this path in you file browser you may find two entires for the same path. Chances are you found one, made a change to the signature.psd file but the system is actually looking at the other one when the action runs.
Simply make the same change to the other Signature.psd file.
I'm currently looking at what can be done to avoid this problem considering the limitations imposed by the operating system and the Photoshop application.