a) Make sure that you uploaded *all* of the 2.2 files.
b) On Options->Reading, try turning off "WordPress should compress articles (gzip) if browsers ask for them" and see if that helps.
c) Various plugins and other things have been known to cause this issue in the past. Disable your plugins and reenable them one by one until you find the culprit.
d) Various Firefox extensions have also caused this error in the past. Upgrade all your extensions. Failing that, disable them and reenable them one by one.
Until you find the cause of the problem, it will not be fixed.
Because the short of it is that we don't have this problem. It works fine for me, for example. So I cannot tell you what's wrong. You have to tell us what's wrong, so that we can tell you a workaround or maybe even make a fix for it for the next version of WordPress. Just saying "it don't work" is less than helpful.