This is probably a little too late to add this, but it may help for to add a warning to those who wish to create new fonts or to the few people who are of the curious nature...

If you try to open any of the flip clock image files (in an external image veiwer), you run the risk of changing the file extensions and the result can lead to none responsive digits or even see the "image not found" message.

The image files are named in the following format flipclock.png.1

If you remove the .1, then you will be able to see these in and external viewer but then when try to save and rename them, you may find that the extension will change to format flipclock.png.1.png

QBW will not be able to see these when you add them to the clock, so you will have to go back in to the queen beacon/dir/ folder and rename the affected images back to format flipclock.png.1

Hope this helps