Lost Categories after uprading to 2.6.2

Hello

I’ve recently upgraded my blog(s) from 2.3.2 and I’m facing the problem that all my categories seem to be gone. I’ve already read all the reports on that topic on that problem but none of them helped.

Situation:

• All posts are shown as uncategorized
• Admin area clearly indicates that there are categories but none of them are shown (see picture below)

This is what my admin area loooks like now:

Please notice the category pagers. Adding a new category makes it appear in the list initially and vanish after a page refresh. Digger depper in mysql revealed this:

mysql> select * from wp_term_relationships limit 1;
+-----------+------------------+------------+
| object_id | term_taxonomy_id | term_order |
+-----------+------------------+------------+
|        24 |                3 |          0 |
+-----------+------------------+------------+
1 row in set (0.02 sec)

mysql> select * from wp_term_taxonomy where term_taxonomy_id = 3;
+------------------+---------+----------+-------------+--------+-------+
| term_taxonomy_id | term_id | taxonomy | description | parent | count |
+------------------+---------+----------+-------------+--------+-------+
|                3 |       3 | category | BioWare     |      6 |    13 |
+------------------+---------+----------+-------------+--------+-------+
1 row in set (0.01 sec)

mysql> select * from wp_terms where term_id = 3;
+---------+---------+---------+------------+
| term_id | name    | slug    | term_group |
+---------+---------+---------+------------+
|       3 | BioWare | bioware |          0 |
+---------+---------+---------+------------+
1 row in set (0.00 sec)

mysql> select * from wp_posts where id = 24;
+----+-------------+---------------------+---------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-------------------------------------------+---------------+--------------+-------------+----------------+-------------+---------------+-------------------------------------------+---------+--------+---------------------+---------------------+-----------------------+-------------+-------------------------+------------+-----------+----------------+---------------+
| ID | post_author | post_date           | post_date_gmt       | post_content                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 | post_title                                | post_category | post_excerpt | post_status | comment_status | ping_status | post_password | post_name                                 | to_ping | pinged | post_modified       | post_modified_gmt   | post_content_filtered | post_parent | guid                    | menu_order | post_type | post_mime_type | comment_count |
+----+-------------+---------------------+---------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-------------------------------------------+---------------+--------------+-------------+----------------+-------------+---------------+-------------------------------------------+---------+--------+---------------------+---------------------+-----------------------+-------------+-------------------------+------------+-----------+----------------+---------------+
| 24 |           2 | 2007-11-29 14:02:23 | 2007-11-29 13:02:23 | <a href="http://foobar.com/wp-content/uploads/2007/11/bioware.jpg" title="bioware.jpg"><img src="http://foobar.com/wp-content/uploads/2007/11/bioware.thumbnail.jpg" style="float: right; margin-left: 8px; margin-bottom: 8px" alt="Greg Zeschuk and Ray Muzyka" /></a>In a recent Interview with <a href="http://gameinformer.com">GameInformer</a>, BioWare's President Greg Zeschuk and CEO Ray Muzyka admitted to be avid WoW Players and fans of the game but they also stated that they find some aspects of the game too tedious and time consuming and hope that BioWare can do better.

... Skipping rest here

So from looking at the database, the relationships between term_taxonomy, terms and posts seems to be ok. So (please excuse my outburst) what the hell is going on here??

Any help would be greatly appreciated.