Sub-directories in a skins directory
If you have sub-directories (e.g. "banners") within one of your registered skins directories, and you disable debug mode, you must have the "recursive" option set in skins.zcml for plone to traverse into the sub-directory, e.g.:
<cmf:registerDirectory
name="netsight_bestofbelron_custom_images"
recursive="True"
/>

