The panels that are provided in the CS4 versions of the Greeting Card Designer provide a wonderful easy to use interface to the Actions palette.
The panels are developed using some beta development code that is provided by Adobe Labs. As a new development product and Photoshop CS4 function, there are bound to be minor annoying issues.
The Support section of the website provides troubleshooting and tips for working with Panels.
With the exception of providing a nice interface to the Actions Palette, the panels do not provide any functionality to the program. If you experience problems with the panels, know that you can always run the actions directly from the Actions Palette.
Also see:
Problems with Panels (CS4)
CS4 Panels Not Working Properly
I Can't Find the One-Click Panels
Error: Function not in this version