Help getting to Current

Hi!
    I've recently installed FreeBSD 5.1 on a new dual-opteron PC (an MSI K8T
Master-FAR2 motherboard).  However, I'm having trouble getting current.  The
pre-built cvsup binary I installed with pkg_add fails with this error:
    ELF interpreter /libexec/ld-elf.so.1 not found
    Abort

    Are there any good workarounds for getting the latest current source?
I've grabbed the 5.2.1 release /usr/src, but that's failing like this:

    cc -O -pipe  -DLINEMODE -DUSE_TERMIO -DDIAGNOSTICS -DOLD_ENVIRON  -DENV_HACK  -I/usr/src/libexec/telnetd/../../contrib/telnet -DINET6 -DAUTHENTICATION -DENCRYPTION -DKRB5 -DFORWARD -Dnet_write=telnet_net_write -Wsystem-headers -Werror -Wall -Wno-format-y2k -Wno-uninitialized   -o telnetd global.o slc.o state.o sys_term.o telnetd.o termstat.o utility.o authenc.o -lutil -ltermcap /usr/obj/usr/src/libexec/telnetd/../../lib/libtelnet/libtelnet.a -lmp -lcrypto -lcrypt -lpam -lkrb5 -lasn1 -lroken -lcom_err
    authenc.o: In function `net_encrypt':
    authenc.o(.text+0x36): undefined reference to `nclearto'
    authenc.o(.text+0x3f): undefined reference to `nclearto'
    authenc.o(.text+0x6e): undefined reference to `nclearto'
    *** Error code 1

    Stop in /usr/src/libexec/telnetd.
    *** Error code 1

    Stop in /usr/src/libexec.
    *** Error code 1

    Stop in /usr/src.
    *** Error code 1

    Stop in /usr/src.
    *** Error code 1

    Stop in /usr/src.

    Help! :-)

        Quincey