There are a few culprits when password resets don't work. The biggest offender is usually an extra space before your actual password begins.
It might look like this:
" ResettingMyPasswordShouldBeEasy" <--- Incorrect, leading spaces
"ResettingMyPasswordShouldBeEasy" <--- Correct!
If that's not the case, you may have requested a password twice, invalidating the first password emailed to you by our system. If this is the case or something else, just email firstname.lastname@example.org and we will help out however we can.