Just because you cannot get Photoshop, GIMP or whatever image-editing program to properly open up an image component from Theme Builder doesn't mean it's impossible to create these components for your custom theme.
If you want to create image components for Theme Builder, this is what you have to do:
1. Let's say you want to add Home Screen background to the 9700. First, hover your mouse over the background image component. The name and dimensions of this image will pop up. The name is not important. What is important are the dimensions, which should be 480x360.
2. Open up your image-editing software (whatever your preference) and create an image that is 480 pixels wide by 360 pixels high.
3. Save/Export your image as a PNG. (For images that fill the entire screen or have no transparent parts, you'll want to save as a PNG-8 file. For images that have transparent/translucent parts, use PNG-24.)
4. Going back to Theme Builder, click on the Home Screen background component and then select your new background image from whatever folder you saved it in.
You can do this for most of the components in Theme Builder.
