Previous Header Logo images not available

My previously uploaded Background Images are always displayed in the “Uploaded” tab under the Background Image section of the Customize panel, but not so with previously uploaded Header Logos.

The “Uploaded” tab under Header Logo with consecutively uploaded logos will appear only until I “Save & Publish”. When I return after I “Close” the Customization panel, there is no “Uploaded” tab, so the only way for me to switch logo images is to repeatedly upload the same images.

I’ve loaded half a dozen logos and background images via the Customize panels and I can see all these previous images (including duplicates) in the media library via the main WP dashboard, so uploading seems ok.

I’ve tried disabling all plugins, tried the default smpl-skeleton and theme, and un-selecting “Organize my uploads into month and year based folders” in Settings > Media. Permissions are 644 on all these header and background images. Also switched to default theme TwentyFourteen and my media library images appear as choices in that theme’s Header Image choices, so pretty sure the media library is ok, although there seem to be lots of problem posts with media library elsewhere.

Smpl-skeleton 2.1.0
Wordpress 3.9.2
PHP 5.3.20