freebsd-update problem 8.0Beta1 to 8.0Beta4

[Fernando Apesteguía]

Hi all,

I'm having some problems trying to update from FreeBSD 8.0 Beta1 to 8.0 Beta4.

I upgraded from 7.2 to beta1 some time ago, using freebsd-update
without problems. Later
I did the same thing to reach beta2. Yesterday I tried it to get to
beta3 but I have a bunch
of errors like this one:

/usr/sbin/freebsd-update: cannot open files/.gz: No such file or directory

This is after the "preparing to download files" stage. I have plenty
of disk space left on my hard disk.
In an attempt to fix the problem I performed a rollback, so I went to
beta1 again. This process seemed
to work fine. However, whenever I try to upgrade to another higher
release number, I get those errors.

Listing the contents of the /var/db/freebsd-update/files/ directory
shows a bunch of .gz files.
What can be wrong?

I've googled, but I haven't been able to find a solution.
Any help?
Thanks in advance.