Mail on 10.7.3 has decided (for some reason) to show several mails of mine sent years ago (like 2010) as having been sent on 30 March 2012.
In the mails themselves, the correct date is shown (under sender, i.e. me, and subject line).
What did Mail do to sort those mails under 30 March 2012 (that might have been the day I upgraded to Lion)?