After I changed some switches in my network munin just doesn't work anymore, i don't see the relation..
In munin-update.log i can see a lot of this :

Dec 31 10:02:22 [29075] - Unable to update /var/lib/munin/ not a simple integer: 'setattr.value lookup.value access.value readlink.value read.value write.value create.value mkdir.value symlink.value mknod.value remove.value rmdir.value rename.value link.value readdir.value readdirplus.value fsstat.value fsinfo.value pathconf.value commit.value '

I can telnet the host and fetch manually

Any ideas?