freebsd-update not working from 7.1-PRERELEASE

[Markus Oestreicher]

I installed 7.1-BETA-i386 from CD and used freebsd-update to get the latest
prerelease updates.

This got me to the following version:

$ uname -a
FreeBSD hostname 7.1-PRERELEASE-p1 FreeBSD 7.1-PRERELEASE-p1 #0: Sun Oct  5 12:15:12 UTC 2008     root at i386-builder.daemonology.net:/usr/obj/usr/src/sys/GENERIC  i386


Now I wanted to go to BETA2, but freebsd-update does not work any more:

# freebsd-update fetch
Looking up update.FreeBSD.org mirrors... 1 mirrors found.
Fetching metadata signature for 7.1-PRERELEASE from update1.FreeBSD.org... failed.
No mirrors remaining, giving up.

# freebsd-update upgrade -r 7.1-BET2
Looking up update.FreeBSD.org mirrors... 1 mirrors found.
Fetching metadata signature for 7.1-PRERELEASE from update1.FreeBSD.org... failed.
No mirrors remaining, giving up.

I thought it was possible to upgrade this way up to 7.1-RELEASE?

Any idea?

Best Regards,
Markus