On 1.4beta after emerge sync, emerge -pu world fails because the /usr/portage/profiles/xxxxx link points to a profile that has been removed (I forgot the actual name). I rm'd /etc/make.profile and relinked to /usr/portage/profiles/default-x86-1.4. I hope this is the right profile?
*** This bug has been marked as a duplicate of 7643 ***