Bug when editing existing Tandem component

[acoleman]

When editing an existing Tandem component that is either a Fade or Stack style (one that was created -before- the "Basic" option was added), user will receive an error stating that they cannot save the changes unless they choose selections for:
Image Position
Add Image Shadow
Shadow Position
Shadow Style

If you flip to basic and choose options for each of those, then switch back to the option you were editing, it will save, but not until then.

This issue does not happen when creating new Tandem components of type Fade or Stack.