Developer's Guide
There are quite a number of components used in order to create the Zenoss interface, and it can be quite a challenge to understand what's happening and how to fix issues. The following are a list of some simple debugging tips:
Use page templates rather than full HTML pages whenever possible. There are a number of dependencies between CSS, JavaScript and other components, and doing it the hard way can be really hard. Trying to do things the hard way in a cross-browser fashion is exceptionally difficult. As a side benefit, using the page templates means that your pages will benefit from any improvements in the base product.
Run Firefox Version 3.x or later, and examine the Error Console to find out what JavaScript errors are occurring. There will be tons of CSS issues coming from different CSS pages (it's annoying, but not fatal), but you can safely ignore them.
The Firefox Error Console will not tell you if Firefox wasn't able to find or load a JavaScript file (if the path you've specified in your Web page to get to the JavaScript file is incorrect). In order to determine if Zope was given a path to a filename that it couldn't find, you'll need to go into Zope's ZMI, go to the error log (http://yourzenossserver:8080/error_log/manage) and remove all of the error log filters. After you do that, retry the operation and you can see what files Zope wasn't able to find and fix the paths in your page.