Trouble while updating Firefox

["Rocky Hotas" <rockyhotas%post.com@localhost>]

Hello!!
I installed Firefox as a normal package with pkg_add some time ago. I run NetBSD 6.1.4.
Now, in order to update the package, I followed this

https://wiki.netbsd.org/pkgsrc/how_to_upgrade_packages/#index1h2

guide, and I ran

pkg_add -uu firefox

The process failed due to some errors with the dependencies and now Firefox is no more installed! So not just the update failed, but I (apparently) lost the original package installation.
I don't have the original error message, but if now I simply try to run

pkg_add firefox

the following error message results:

pkg_add: Warning: package `firefox-38.0.5' was built for a platform:
pkg_add: NetBSD/i386 6.1 (pkg) vs. NetBSD/i386 6.1.4 (this host)
pkg_add: Warning: package `pulseaudio-6.0nb1' was built for a platform:
pkg_add: NetBSD/i386 6.1 (pkg) vs. NetBSD/i386 6.1.4 (this host)
pkg_add: Warning: package `speexdsp-1.2rc3' was built for a platform:
pkg_add: NetBSD/i386 6.1 (pkg) vs. NetBSD/i386 6.1.4 (this host)
pkg_add: Conflicting PLIST with speex-1.2rc1nb1: include/speex/speex_echo.h
pkg_add: Can't install dependency speexdsp>=1.2rc3
pkg_add: Can't install dependency pulseaudio>=6.0
pkg_add: 1 package addition failed

and the installation fails again. How can I do to restore Firefox?
Thanks anyway,

Rocky