Hi,
Not sure what is meant from the description. Does the password field not let you write anything at all?
Worst case: A keystroke logger can mess up password fields, paranoid/suspicious experience leads me to believe, albeit with no facts to back the improbable (?) theory up...
On a more rational level: Have you changed any software on your computer or are you using a different browser? I find sometimes what I write is not introduced faithfully to username and/or password fields, it seems to be something glitchy about either a piece of keystroke scrambling software I use or a browser or I think it's the combination of the two that don't always "speak the same language". One browser is hopeless for this kind of thing, it writes whatever letters it feels like sometimes in both fields but refreshing the page sorts the issue out. I wonder if it's writing before a page is fully loaded sometimes as well so I think I've written it correctly but there are letters, sorry - alphanumeric characters - missing.
And sometimes I make fat finger mistakes...
(Let's hope edaboard never gets the captcha disease - allegedly proven to be useless against machines and hard for humans to do correctly... grrrrrr!)