Password not working

I logged in to the Forums using my password (typing it afresh). So, clearly, I do KNOW my password. Then I tried to change my profile email, carefully confirming, etc. I got either 'passwords do not match' or 'the password you entered does not match the password in the database.'

Well, I've tried around 20 times, and I can't get the system to accept the password. It simply won't.

I applied for a new password, logged in with that, entered that in the 'change email' box , and it didn't work either.