have you followed the install guide
http://www.archlinux.org/docs/en/gui...tall-guide.htm
" During package installation, pacman fails to resolve dependencies for package A because package B is not in the package set
Unless something is very broken and thus very likely to be reported by multiple people soon, you probably just forgot to mount your target partitions properly. This causes pacman to decompress the package database into the initial ramdisk, which fills up quite nicely and ultimatively leads to this error.
Make sure that you use the DONE and not the CANCEL option offered by the Filesystem Mountpoints menu to apply your choices. This error should not happen if you use the Auto-Prepare feature; please report this as a bug. "