Upgrading to 2.7.1 from 2.6.3 broke my blog: character encoding came all messed up (as the blog is in French, there are many accented characters), and the (very simple) theme didn’t work correctly anymore.
As the WP export function does not work correctly (output is severely truncated – this has been indicated for years without a solution), I had to restore everything back to the older version, using split SQL files, table by table (as the SQL backup dump was too large for the phpMyAdmin to ingest at once).
A mess. As time goes by (and a blog grows) it is increasingly harder to maintain consistency of contents through releases.
