I tried to sign into Mt. Gox today and it is telling me invalid username and password but I have not changed them and this is the same info I have been entering and it was working until a few hours ago. I used the forgot password button to reset password but password reset was not emailed to me. I then tried Mt. Gox support desk and also can't login same error invalid username and password. Seems kind of fishy to me since I never changed anything and now can't log in. Also no response from Mt. Gox. I usually get response within minutes from gox support. Anyone else experiencing issues with Gox.
The fact that you didn't get the email is messed up; if someone did manage to get into your account, that's the first thing they would do, change email settings..
Get on IRC and talk to any of the support people there..