From 4.6.3 to 4.7.2 Update #180

Hello,
I'm trying to update my drupal site, from 4.6.3 to site test 4.7.2, but i have differents problems:
First my original DB is in latin1_swedish and it seems corrupt (but the website i can see perfect), the charset like ñ in the DB is Á~, for example. From phpmyadmin the backup is in UTF8 and it saved the wrong charset in UTF8 (impossible to fix). If I do the backup with the module Database in drupal 4.6.3 the SQL file is in ANSI and converter to UTF8 with notepad++ and the charset is OK. Then I import to my test database for 4.7.2 update, DB in UTF8 (without the search tables, mysql have a problem some entries, well i put empty tables and later it'll reindex, ok?).
I upload 4.7.2 in the test site and I go to update. Update selects system module #129, then Iclick in update and I get this failed:

    * user warning: Incorrect table definition; there can be only one auto column and it must be defined as a key query: ALTER TABLE node DROP PRIMARY KEY in /home2/squealer/public_html/dietascd-com-es/test/includes/database.mysql.inc on line 120.
    * user warning: Multiple primary key defined query: ALTER TABLE node ADD PRIMARY KEY (nid, vid) in /home2/squealer/public_html/dietascd-com-es/test/includes/database.mysql.inc on line 120.

And:

Update #180
    * Failed: ALTER TABLE {node} DROP PRIMARY KEY
    * Failed: ALTER TABLE {node} ADD PRIMARY KEY (nid, vid)
    * ALTER TABLE {node} ADD UNIQUE (vid)
    * ALTER TABLE {node} ADD INDEX (nid)
    * ALTER TABLE {node_counter} CHANGE nid nid INT(10) NOT NULL DEFAULT '0'

Is it a problem for it to work fine in the future drupal 4.7.2 ?
Maybe it is a problem to convert DB from ANSI to UTF8 ?

Thank you and sorry for my english.