I got this from http://kb.mozillazine.org/RSS_basics_-_Thunderbird
and it says:
Creating an RSS News & Blogs account
Before you can subscribe to any RSS feeds, you first need to create an RSS account. To do so:
1. Go to the "File" menu and select "New -> Account". Alternatively, you can go to the "Tools" menu and select "Account Settings", and click on the "Add Account" button.
2. In the dialog box that pops up, select "RSS News & Blogs" and press the "Next" button.
3. Enter an account name, press the "Next" button, and finally press the "Finish" button. This new account will now appear in the folders pane in the main Thunderbird window.
Note: if the option to create an RSS account does not even appear, it is probably because you chose a "Custom" (rather than "Standard") install of Thunderbird, and you did not select to include RSS Support in your installation. In that case, you should uninstall Thunderbird and reinstall it, making sure to include the RSS option this time.
In the note it says that I need to reinstall it using 'custom' installation and I should now include RSS support. I tried to completely remove and reinstall it using synaptic but I still was not prompted for the custom install.
What I want to do now is to do a manual install. I have downloaded the source files from mozilla and extracted it to a directory. Can you please help me on how to proceed with the manual install? thanks...