Failed queries while upgrading from 5.22 to 6.17, on a Postgres (8.2.9) Database

Hi!

We´re trying to upgrade a Drupal 5.22 installation to the 6.17 version, but we´ve got some failed queries when running the update.php script.

Below are the reported problems ...

Update #6002

* Failed: ALTER TABLE {variable} DROP CONSTRAINT {variable}_pkey

Update #6030

...
* Failed: CREATE TABLE {actions_aid} ( aid serial CHECK (aid >= 0), PRIMARY KEY (aid) )

Update #6043

...
* Failed: ALTER TABLE {locales_target} ADD PRIMARY KEY (language,lid,plural)
...
* Failed: ALTER TABLE {term_node} ADD PRIMARY KEY (tid,vid)

Besides that, we´ve got lots of warnings related to syntax errors as well ...

We are running Postgres version 8.2.9.

How can we solve these issues?

Thanks in Advance,
Carlos Zottmann.