Trage doch mal den archlinux.org-Server in die pacman.conf ein. Bei mir sieht das wie folgt aus:
[current]
# Add your preferred servers here, they will be used first
#Include = /etc/pacman.d/current
Server = ftp://ftp.archlinux.org/current/os/i686
[extra]
# Add your preferred servers here, they will be used first
#Include = /etc/pacman.d/extra
Server = ftp://ftp.archlinux.org/extra/os/i686
[community]
Server = ftp://ftp.archlinux.org/community/os/i686
Danach nochmal
pacman -Syu ausführen.