The "OK" button in the Background dialog is not always
enabled when it should be. To reproduce:
1. Bring up the Background dialog (from the "Text Area"
panel in the Options dialog).
2. Select the "Image" radio button.
3. Click the "Cancel" button.
4. Bring the Backgroun dialog back up.
"Color" will be selected (as expected) but the OK
button is disabled when it should be enabled.