You can update to Firefox 24, just released today (Help > About).

You can try basic steps like these in case of issues with web pages:

Reload web page(s) and bypass the cache to refresh possibly outdated or corrupted files.

• Hold down the Shift key and left-click the Reload button
• Press "Ctrl + F5" or press "Ctrl + Shift + R" (Windows,Linux)
• Press "Command + Shift + R" (Mac)

Clear the cache and the cookies from websites that cause problems.

"Clear the Cache":

• Firefox/Tools > Options > Advanced > Network > Cached Web Content: "Clear Now"

"Remove Cookies" from sites causing problems:

• Firefox/Tools > Options > Privacy > Cookies: "Show Cookies"

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Firefox/Tools > Add-ons > Appearance).

• Do NOT click the Reset button on the Safe Mode start window.

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

So I went through all the steps you listed above and the problem still exists I noted that the Java development tool is disabled and I would have no use for it anyway. I updated all the add-ons and Firefox as well. started in safe mode and the problem remains. BUT the mail will now allow clicks and allow me to compose but still only the top 6 e mails appear on the page. Do you think the idiots at Yahoo tried to improve their product AGAIN and messed it up???

I figured since Yahoo changed the background color of my e-mail without my permission they must be guilty of messing this up as well, so I started punching options and buttons in Yahoo till I figured out it was a "pre-view pane" that they had defaulted to. I am so sorry for bothering you, but at least i got Firefox tuned up and love it to death. Thanks again for your help best regards, Ken