Due to upgrading Coppermine Gallery to the latest version, v1.4.19, on December 26, 2008, the registration was broken. Anyone who attempted to register and was told there was a “confirmation code did not match” scenario, you can now register. The problem laid in the older versions of Coppermine that did not look for captcha during registration but only during login. Somehow, that part got fixed in the latest version, but they forgot to add the fix to the captcha plugin.
Anyway, everything is hunky-dory again. You may register, if you haven’t done so. Remember, captcha code input is all lowercase letters. Inputting the code in all uppercase will not go through.