You're using a library such as Dojo in addition to your functionality. The Dojo effect, such as the fisheye toolbar, doesn't work. Where's the first place to look to see how there might be a conflict between your code and Dojo's?
In the Prototype library, what does the $( ) function do?
The fisheye application created using Dojo does not validate as XHTML. The custom attributes on the DIV elements are accountable for much of this. What is a workaround?
How does the Yahoo! UI Library work around the same-domain security policy but still allow access to web services at other domains?
So, does MochiKit make JavaScript "suck less"? Seriously, what's your view on the strengths and weaknesses of JavaScript now that you've read a book about it?