I see these types of messages all the time on library-related websites, and I agree that it sends the message that those who manage those sites don’t have a good grasp of current web technology:
Time to Update? by David Lee King.
Check the web sites that your library presents to the world. If you see messages like those highlighted by David, start talking to people about getting them up to date (or better yet, getting rid of them, since a good standards-designed site will work well across browsers and browser versions).