You may not have Internet Explorer as your default browser but it is coded with Yahoo Messenger
For this reason you must keep it up to date and the support software as well. You do not have to set it as default but you need to keep itclean.
Flashplayer FOR IE
Shockwaveplayer FOR IE
Check out the Yahoo Messenger Scripting Help page
1) Visit this page and select your product version (Messenger version) using the drop boxhttp://help.yahoo.com/kb/index?page=prod...
2) Type into the search bar: ......... script error...........and hit 'Search'
3) Browse the section for your problem and your OS and click on the link
To enable scripting:Internet Explorer8
Click "Internet Options."
Click "Security" tab.
Click "Custom Level" button.
Scroll down to "Script ActiveX.controls marked safe for scripting"- enable
Scroll down to "Scripting - Active scripting" - enable
Scroll down to "Scripting of Java applets" - enable