Custom images not loading on "Save Changes"

Hi,

Just completed a new multisite install. Installed Ultimate Branding. Custom images do not load on "Save Changes". I've checked folder permission, image type (png), subsite and network activated, images can be uploaded to Image Library.

If I ftp images to appropriate folder, they display correctly. But if I reset, images disappear (as they are supposed to) but a new image cannot be uploaded through the gui.

Any ideas?
Thanks!