If a customer calls and tells you that she cannot see some content of her website beware of the following before starting tcpdump
or other forensic debugging tools.
Some ad blockers like Adblock Show archive.org snapshot are shipped with filters that remove (amongst others)
divs
named 'sponsor'
"banner"
or the filename "banner.png"
'sponsor*'
adv_...
.Renaming the div
to something more specific to your site and renaming the directory should fix the issue. Pardon me! It fixes the feature.