It seems someone is systematically trying to guess passwords on this site.
To make sure you don’t fall victim to these idiots, please do the following:
Make sure your password is not a word found in a dictionary. If it is, change it now by clicking here. Even something as simple as adding a number to a password will make it more difficult to guess.
Make sure your e-mail address (in your profile) is valid and up to date. If your account is disabled for any reason, this is the only way you can reset it. Check this now by clicking here to check your profile.
Finally, if you’re tired of entering your password over and over, and doing the CAPTCHA, you can login in permanently by clicking on login on the top menu, and then selecting “Log me on automatically each visit”.