If you check the armv6 download area here:
You can see that there are problems:
# *-raspberrypi images are outdated whereas newer images are build ok
has been built)
# We have outdated *armv6-rootfs.armv6l* images AND newer
I think the publish script has some problem with *-raspberrypi and we
should remove old rootfs images.
I wanted to fill a bug but I do not know which category to use.