IE8 Optimized for Yahoo is not available foe Win 7 64 bit according to the link.
"The Yahoo! optimized version of Internet Explorer 8 is only available for the following operating systems:
- Windows XP 32-bit Service Pack 2 (SP2) or higher
- Windows Vista
- Windows Vista 64-bit
- Windows Server 2008
- Windows Server 2008 64-bit "
Additional info
Links internal to GMAIL email also do not work.
Links on Yahoo home page do work
After loging into Yahoo mail the Mail Help links, Contact us and Feedback do not work.
I have disabled all add-ons in IE8 and links internal to mail still do not work.
If I use Firefox then open Yahoo the links do work.
Bottom line this must be an IE8 problem as the mail sites work under Firefox