abo-73-21-68 linux # emerge --update --deep --newuse world
Calculating world dependencies /
!!! Problems have been detected with your world file
!!! Please run emaint --check world


!!! Ebuilds for the following packages are either all
!!! masked or don't exist:
media-video/gspcav1 net-misc/networkmanager net-misc/dhcdbd

... done!

!!! Error: the x11-drivers/xf86-video-i810 package conflicts with another package;
!!!        the two packages cannot be installed on the same system together.
!!!        Please use 'emerge --pretend' to determine blockers.

For more information about Blocked Packages, please refer to the following
section of the Gentoo Linux x86 Handbook (architecture is irrelevant):

http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?full=1#blocked