Supporting mulitple versions of Firefox (2.*, 3.*). What should I test?

I have a situation in which I did web development (Wicket running on Tomcat) on Firefox 3.6.3, and now need to support Firefox 2.0 as well. Do you have any tips on what I should expect to break开发者_如何学JAVA or where I should focus my testing?

Here's a few discrepancies to test between Firefox 2 and later versions:

• Use white-space: -moz-pre-wrap for Firefox 2 to emulate white-space: pre-wrap in Firefox 3+
• Text in Firefox 2 Mac with opacity set has reduced contrast
• Use display:-moz-inline-box in a separate declaration to trigger the Firefox 2 experimental layout which approximates display:inline-block for a particular element.
• Add a fixed width div nested in the wrapper to address the limitations of -moz-inline-box in Firefox 2.