odd port list installed output

[skip at pobox.com]

In my previous email I wrote:

    If I decide to reinstall, is there some way I can record what ports I
    currently have installed then, after the basic install, reinstall those
    ports with one command?

So port list installed seems to spit out something almost like what I need,
but I noticed that I seem to have two copies of several ports installed.  It
looks like fftw-3, oss-uuid, python24 and python25 are all installed twice:

    % port list installed
    bison                          @2.3            devel/bison
    bzip2                          @1.0.4          archivers/bzip2
    db44                           @4.4.20         databases/db44
    expat                          @2.0.1          textproc/expat
    fftw-3                         @3.1.2          math/fftw-3
    fftw-3                         @3.1.2          math/fftw-3
    freetype                       @2.3.5          print/freetype
    g95                            @0.90           lang/g95
    gdbm                           @1.8.3          databases/gdbm
    gettext                        @0.17           devel/gettext
    jasper                         @1.701.0        graphics/jasper
    jpeg                           @6b             graphics/jpeg
    libiconv                       @1.12           textproc/libiconv
    libpng                         @1.2.25         graphics/libpng
    libxml2                        @2.6.31         textproc/libxml2
    libxslt                        @1.1.22         textproc/libxslt
    m4                             @1.4.10         devel/m4
    mercurial                      @0.9.5          devel/mercurial
    ncurses                        @5.6            devel/ncurses
    ncursesw                       @5.6            devel/ncursesw
    netpbm                         @10.26.50       graphics/netpbm
    openssl                        @0.9.8g         devel/openssl
    ossp-uuid                      @1.6.0          devel/ossp-uuid
    ossp-uuid                      @1.6.0          devel/ossp-uuid
    postgresql83                   @8.3.0          databases/postgresql83
    py25-dateutil                  @1.4            python/py25-dateutil
    py25-tz                        @2007k          python/py25-tz
    python24                       @2.4.4          lang/python24
    python24                       @2.4.4          lang/python24
    python25                       @2.5.2          lang/python25
    python25                       @2.5.2          lang/python25
    readline                       @5.2.007        devel/readline
    tiff                           @3.8.2          graphics/tiff
    unzip                          @5.52           archivers/unzip
    wget                           @1.11           net/wget
    zlib                           @1.2.3          archivers/zlib

What's up with that?  I suppose I should be able to do something like this:

    port list installed | awk '{print $1}' > currentports
    sudo rm -rf /opt/local
    sudo port install $(cat currentports)

but isn't there some other directory I need to remove?  Some sort of
MacPorts frameworks directory?

-- 
Skip Montanaro - skip at pobox.com - http://www.webfast.com/~skip/