Unable to obtain PowerPC Kernel and System sources

[Shlomi Marco]

Good day.

(newbie here)
I've recently installed FreeBSD 9.1-RC2 from ISO on my iMac G4.
I've later tried to fetch the system and kernel sources via sysinstall,
with no success, I'm getting the following message:

"...Warning:  Can't find the `9.1-RC2' distribution on this
FTP server.  You may need to visit a different server for
the release you are trying to fetch or go to the Options
menu and to set the release name to explicitly match what's
available on ftp.freebsd.org (or set to "any")..."

regardless of the mirror I use or the version I use (e.g 9.1-RELEASE)
Changing to "any" just gives the following error: "Unable to transfer the
sbase distribution"

What am I doing wrong, and how otherwise can I get the sources I need?

Thank you and best regards,
S.