when you try to login, press the i forgot my password button. Answer the questions,or resolve whatever security option you chose and then you can make a new password. Or if you provided them with another email for confirmation when you created your yahoo account,they will send a link for a new password to that address.
Also make sure you're not typing another password by mistake.
thx. i have done that, but wont let me pass that capcha thing. on other address work without problems. i will try later.