There are a couple of reasons why Address AutoComplete may not work.

Note: Address Autocomplete does not work for Safari, Opera, and non-JavaScript enabled browsers.

A few things to check:

• Is the address that you’re typing in your Address Book? If not, it won’t AutoComplete for you.
• Do you have the latest Yahoo! toolbar? If not, AutoComplete may not work.

Supported Browsers:

• IE 6.0 and above for Windows
• Netscape 7.2 and above for Windows
• Firefox 1.x and above for Windows & Mac

Remember, even if you can’t AutoComplete addresses, you can still insert contacts from your Address Book by clicking on the "Insert addresses" or "To:" links on your Compose page.