problem with gcalctool corupt

[freenity]

Hi there is a problem with my packages, when I try to upgrade it or do
something with it, there is allways this error. WHen trying to install
firefox it showed the same error.

===>   Generating temporary packing list
===>  Checking if www/firefox already installed
pkg_info: the package info for package 'gcalctool-5.8.24,2' is corrupt
===>   An older version of www/firefox is already installed (firefox-1.5.0.8
,1)
      You may wish to ``make deinstall'' and install this port again
      by ``make reinstall'' to upgrade it properly.
      If you really wish to overwrite the old port of www/firefox
      without deleting it first, set the variable "FORCE_PKG_REGISTER"
      in your environment or the "make install" command line.
*** Error code 1

Stop in /usr/ports/www/firefox.
*** Error code 1

Stop in /usr/ports/www/firefox.