images from layout design background are not displayed
I have images (PNG on JPEG) with customized graphic I want to use in Title Header, Header, Footer...
They are correctly displayed in background, if I use FMS13 WebDirect client from my office - (I use both server connections - via internal IP address or public IP/URL). If I use the same public URL from home or from client office, no images in layout background are displayed. But images which are in the database content are displayed everywhere. I tested in IE, Chrome, Firefox and Safari (latest versions), no difference - in office I see background graphics correctly, from remote computers I see only white empty strips.
If I use solid or gradient color background, layout is displayed correctly on all computers.
Any idea what could be wrong on computers/browsers out of office/internal network?