We hope to resolve the matter tonight, but right now, the repository metadata (repodata/) of the individual repositories (Essentials, Multimedia, Extra and Games) is broken because it is not updated correctly.
In the mean time, if you can't wait ;), please use the "top-level"/"big" repositories instead, they're fine.
To be precise: don't use e.g. http://packman.inode.at/suse/openSUSE_11.3/Essentials but use http://packman.inode.at/suse/openSUSE_11.3
Sorry for the inconvenience :\