adblock not getting installed on mozilla

[H.S.]

When I try to install adblock extension in mozilla, the installation 
fails in error. First it reports that there was a permissions problem 
while writing to disc, then it completes installation anyway and 
apparently a restart of mozilla is supposed to have adblock then installed.

However, when I try to adblock some image from some website, adblock 
reports that:
Adblock is not yet enabled:
Make sure the browser is located on a write-accessible disk. ...Then, 
quit and re-launch. the missing Component will be installed, at startup.


I am trying this on Ubuntu:
 > cat /proc/version
Linux version 2.6.15-23-386 (buildd at rothera) (gcc version 4.0.3 (Ubuntu 
4.0.3-1ubuntu5)) #1 PREEMPT Tue May 23 13:49:40 UTC 2006

on my university lab computer where the home drive is networked. I had 
chosen to install the extension in  my profile (not on system root) 
during installation, so I am not sure why this problem is happening.

Here is the install.log file in mozilla directory:
###########################################################
-------------------------------------------------------------------------------
http://adblock.ethereal.net/Adblock_v.5/adblock-05-dev.xpi  -- 
2006-09-08 16:20:03
-------------------------------------------------------------------------------

      pre-install (version 0.0)
      -----------

      [1/1]	Create Folder: 
/home/cirrus/red/.mozilla/default/32kosope.slt/chrome/adblock-temp
      pre-install - 0.0 (version 0.0)
      -----------------

      pre-install - 0.1 (version 0.1)
      -----------------

      pre-install - 0.2 (version 0.2)
      -----------------

      pre-install - 0.3 (version 0.3)
      -----------------

      pre-install - 0.4 (version 0.4)
      -----------------

      pre-install - 0.5 (version 0.5)
      -----------------

      [1/1]	
      pre-install (version 0.5)
      -----------

      [1/1]	Move File: 
/home/cirrus/red/.mozilla/default/32kosope.slt/adblock-uninstalled to 
/home/cirrus/red/.mozilla/default/32kosope.slt/chrome/adblock-temp
      pre-install (version 0.5)
      -----------

      pre-install - 0.6 (version 0.6)
      -----------------

      pre-install - 0.7 (version 0.7)
      -----------------

      pre-install - 0.8 (version 0.8)
      -----------------

      adblock (version 0.5)
      -------

      ** ERROR (-202): Installing: /usr/lib/mozilla/components/.autoreg
      ** ERROR (-202): Installing: /usr/lib/mozilla/components/nsAdblock.js
      [1/6]	Installing: 
/home/cirrus/red/.mozilla/default/32kosope.slt/chrome/adblock.jar
      [2/6]	Installing: 
/home/cirrus/red/.mozilla/default/32kosope.slt/chrome/nsAdblock.js
      [3/6]	Installing: 
/home/cirrus/red/.mozilla/default/32kosope.slt/chrome/.autoreg
      [4/6]	Register Content: 
jar:file:///home/cirrus/red/.mozilla/default/32kosope.slt/chrome/adblock.jar!/content/
      [5/6]	Create Folder: 
/home/cirrus/red/.mozilla/default/32kosope.slt/pref
      [6/6]	Installing: 
/home/cirrus/red/.mozilla/default/32kosope.slt/pref/adblock.js

      Install completed successfully  --  2006-09-08 16:21:59
###########################################################


I have these packages installed related to mozilla:
 > dpkg -l *mozilla* | grep ^ii
ii  j2re1.4-mozilla-plugin            0ubuntu5 
Java plugin for mozilla/firefox
ii  mozilla-browser                   1.7.12-1.1ubuntu2              The 
Mozilla Internet application suite - cor
ii  mozilla-firefox                   1.5.dfsg+1.5.0.5-0ubuntu6.06.1 
Transition package for firefox rename
ii  mozilla-firefox-locale-en-gb      1.5.0.1ubuntu6-2 
Mozilla Firefox English language/region pack
ii  mozilla-psm                       1.7.12-1.1ubuntu2              The 
Mozilla Internet application suite - Per
ii  mozilla-thunderbird               1.5.0.5-0ubuntu0.6.06 
Mozilla Thunderbird standalone mail client


Can somebody hint about what is  going wrong here?
thanks,
->HS