I am using Firefox 3.6.13 on a Windows XP Pro Service Pack 3 computer. This is a Dell Dimension 3000 PC with a Pentium 4 processor running at 2.8 Ghz. . There is 512 MB of ram installed.

I have the yahoo toolbar installed which normally displays the mail icon. Sometimes when I load my browser, the yahoo mail icon does not appear. Also there is a refresh toolbar button on the yahoo toolbar that looks like a gear. Sometimes it works and most other times it does not work, meaning to refresh the toolbar and enable the yahoo mail icon to appear. Why does that happen?