This page, Macromedia - Flash Player Version Information, will show you a small box that says: You have version x,y,z,a installed. (8,0,22,0 is an example, so is 7,0,19,0). Sometimes knowing the EXACT version will help debug your flash woes.
Also, it's possible that you might have different player versions installed on Firefox vs IE.
About:config entries - MozillaZine Knowledge Base This article explains what the different options are that you can control via about:config inside a Mozilla/Firefox browser.
Filtering by password can be useful if your Master Password is messed up.
Mozilla Password Viewing -- this page will let you download a JS script that, if you save locally and run, will display for you all of your usernames and passwords. This could come in handly when switching machines, etc.
S5: A Simple Standards-Based Slide Show System: S5 is a slide show format based entirely on XHTML, CSS, and JavaScript. With one file, you can run a complete slide show and have a printer-friendly version as well. The markup used for the slides is very simple, highly semantic, and completely accessible. Anyone with even a smidgen of familiarity with HTML or XHTML can look at the markup and figure out how to adapt it to their particular needs. Anyone familiar with CSS can create their own slide show theme. It's totally simple, and it's totally standards-driven.