When upgrading misc/mc it fails with following error:
barzog@albatros:~>sudo portupgrade mc
--->  Upgrading 'mc-4.6.1_4' to 'mc-4.6.2' (misc/mc)
--->  Building '/usr/ports/misc/mc'
===>  Cleaning for mc-4.6.2
===>  Found saved configuration for mc-4.6.2
===>  Extracting for mc-4.6.2
=> MD5 Checksum OK for mc-4.6.2.tar.gz.
=> SHA256 Checksum OK for mc-4.6.2.tar.gz.
=> MD5 Checksum OK for mc-4.6.2-utf8.patch.gz.
=> SHA256 Checksum OK for mc-4.6.2-utf8.patch.gz.
===>   mc-4.6.2 depends on file: /usr/local/bin/perl5.8.9 - found
===>  Patching for mc-4.6.2
===>   mc-4.6.2 depends on file: /usr/local/bin/perl5.8.9 - found
===>  Applying distribution patches for mc-4.6.2
===>  Applying FreeBSD patches for mc-4.6.2
===>   mc-4.6.2 depends on executable: pkg-config - found
===>   mc-4.6.2 depends on executable: gmake - found
===>   mc-4.6.2 depends on file: /usr/local/bin/perl5.8.9 - found
===>   mc-4.6.2 depends on file: /usr/local/bin/automake-1.9 - found
===>   mc-4.6.2 depends on executable: pkg-config - found
===>   mc-4.6.2 depends on shared library: slang.2 - found
===>   mc-4.6.2 depends on shared library: iconv.3 - found
===>   mc-4.6.2 depends on shared library: intl - found
===>   mc-4.6.2 depends on shared library: glib-2.0.0 - found
===>  Configuring for mc-4.6.2
/usr/local/share/aclocal/glib.m4:8: warning: underquoted definition of AM_PATH_GLIB
  run info '(automake)Extending aclocal'
  or see http://sources.redhat.com/automake/automake.html#Extending-aclocal
/usr/local/share/aclocal/audiofile.m4:12: warning: underquoted definition of AM_PATH_AUDIOFILE
configure.ac:6: error: Autoconf version 2.60 or higher is required
configure.ac:6: the top level
autom4te259: /usr/local/bin/gm4 failed with exit status: 63
aclocal-1.9: autom4te failed with exit status: 63
*** Error code 63

Stop in /usr/ports/misc/mc.
*** Error code 1

Stop in /usr/ports/misc/mc.
** Command failed [exit code 1]: /usr/bin/script -qa /tmp/portupgrade20090831-59251-zk5pgv-0 env UPGRADE_TOOL=portupgrade UPGRADE_PORT=mc-4.6.1_4 UPGRADE_PORT_VER=4.6.1_4 make
** Fix the problem and try again.
** Listing the failed packages (-:ignored / *:skipped / !:failed)
        ! misc/mc (mc-4.6.1_4)  (unknown build error)

I reinstalled autoconf and autoconf-wrapper and have following versions:
autoconf-2.13.000227_6
autoconf-2.62
autoconf-wrapper-20071109
The problem is here:
barzog@albatros:~>ls -l /usr/local/bin/autoconf
lrwxr-xr-x  1 root  wheel  16 Aug 31 12:45 /usr/local/bin/autoconf -> autoconf-wrapper

barzog@albatros:~>autoconf -V
autoconf (GNU Autoconf) 2.59

Problem occured after portupgrade -a.