Not sure why this problem still seems to persist although there seem to be some coverage of the issue or something like it among . No Yahoo site at all displays correctly in FireFox (1.0.7) for me. However when I installed the [broken link removed] extension and asked FireFox to masquerade as Internet Explorer then Yahoo sites display fine. Not sure why Yahoo would prevent (deliberately or by not addressing the underlying bugs in their sites) FireFox users from viewing their sites when it has been one of the fastest growing browsers in a long time. Oh well, at least there is a workaround other than switching back to IE.