Google desktop does not index web history..?

[monkeyman]

I have experienced this problem with Ubuntu 8.10, Linux Mint, Fedora 11 and Mandriva 2009.0 and those are the only ones in which I have tried Google Desktop. Google desktop's help page says
# Go to your Firefox or Thunderbird extensions directory. For example, if you installed Firefox in /opt/firefox2, go to /opt/firefox2/extensions/
# Run the following commands:

Note: You may need root privileges if your Firefox or Thunderbird clients are installed by the root user.

For Firefox:

I cannot paste the command as it says I am not allowed to post links when I click submit button

I am not allowed to post links so I cannot give links to the help page
But firefox directory is not in /opt/ and I cannot find that directory anywhere. When I installed firefox 3.6 and did what was required it says Google Desktop does not support Firefox 3.6. Is there any place where I can download earlier versions of firefox to solve the problem.

[monkeyman]

the command was ln -s /opt/google/desktop/plugin/firefox/ desktop @ google.com
There is no space between desktop and google.
The Google desktop help page is here desktop.google.com/support/linux/bin/answer.py?hl=en&answer=66149