I wrote a few weeks ago on the support forums about trying to import tags onto 2.3 from ultimate tag warrior and things not working out. I got no response from that.
I found another fault today that I was unaware of of the same variety as the Tag issue -- CATEGORIES aren't being read in WordPress. I'm not saying it's the noted DB error from unsupported themes. This is in the WordPress Admin control panel in the MANAGE > Categries area:
WordPress database error: [Table 'stickswp.wp_categories' doesn't exist] SELECT SQL_CALC_FOUND_ROWS * FROM wp_categories WHERE category_parent = '0' ORDER BY cat_name LIMIT 0, 50
That appears at top of the menu where the categories should be listed. Below that is the category table -- which is completely empty.
The site, http://www.Sticksoffire.com , has been running fine in general and operating fine from a user perspective since the upgrade... Just these bumps on the road keep things a little screwed up from the admin perspective.