User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9) Gecko/2008052906 Firefox/3.0 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9) Gecko/2008052906 Firefox/3.0 Dynamic loading of options categories breaks when after clicking on Options the user immediately starts clicking on the different categories in the options panel (Main, Tabs and then jump to Security, Advanced). The result is some exceptions being thrown and blank panels for Security and Advanced. I guess it only happens when the system starts Firefox 3 for the first time and loads all UI. Reproducible: Always Steps to Reproduce: 1. Start firefox 3. (Maybe need to restart and start it for the first time) 2. Click on Options and quickly start clicking on the categries. 3. Observe how some categories show blank panels and also there are exceptions shown in the error log.