@valent, did you find anything?
I had a nightmare experience when I tried updating WordPress 2.71 and spent over a full day troubleshooting in an effort to get it back up and running. I ended up having to just reinstall 2.71 and restore the backup.
I wasn't going to ever risk an update again as I am really happy with 2.71.
However, I have heard a lot recently about the huge security vulnerability in older versions of WordPress and am once again considering upgrading from 2.71 to the latest version.
But I am being much more cautious this time and investigating all the problems others have had before I decide to go ahead with another upgrade.
I could wait to be hacked, or risk destroying it myself with a failed upgrade.
Did you get this issue resolved?