No, there is just a discrete "Blocking ads? :(" link where the ads normally are, linking to http://www.imcdb.org/help.php?supportnotice
I don't want to annoy visitors, but I want them to know that normally the site relies on ads.

lijit.com is the main source of ads since two months now, so if there is a problem with it now it is just an unfortunate temporary problem. Compared to the previous ad provider, it was less annoying when the page was loading: its ads used to load after the page instead of blocking it in the middle.