Content all lost updating from 4.6.0 to 4.6.9

Was going to upgrade to 4.7.3 but read on the forum that I should upgrade to the lastest 4.6.x. So I did install 4.6.9.

The first time I ran "update.php", I got error messages from the "include/database.mysql.inc" script saying that it had encountered duplicates in the "sessions" table when trying to insert a record. It seems to me that the "sid" field got resized from 10 to 33. I fixed the column size and the error went away.

After running "update.php", the report I get seems to indicate that the update went OK:

Drupal database update

    * main page
    * administration pages

2005-04-14

2005-05-06

2005-05-07

ALTER TABLE {locales_source} CHANGE location location varchar(255) NOT NULL default '' 
OK


Updates were attempted. If you see no failures above, you may proceed happily to the administration pages. Otherwise, you may need to update your database manually.

However, now I get this in the main page:

{head} {styles}
{_BLOCK_.header.logo} {_BLOCK_.header.site_name} {_BLOCK_.header.site_slogan} 	
{secondary_links}
{primary_links}
{_BLOCK_.header.search_box}
{_BLOCK_.footer.blocks}

Welcome to your new Drupal-powered website. This message will guide you through your first steps with Drupal,
and will disappear once you have posted your first piece of content.

The first thing you will need to do is create the first account. This account will have full administration rights and 
will allow you to configure your website. Once logged in, you can visit the administration section and set up your 
site's configuration.

Drupal comes with various modules, each of which contains a specific piece of functionality. You should visit the 
module list and enable those modules which suit your website's needs.

Themes handle the presentation of your website. You can use one of the existing themes, modify them or 
create your own from scratch.

We suggest you look around the administration section and explore the various options Drupal offers you. For 
more information, you can refer to the Drupal handbooks online.
{_BLOCK_.footer.message}

It seems that I've lost all my content. What have I missed? How do I eventually get it to 4.7.3?