Locked out of my site – Errors all over

This error has just started, nothing has been changed on the site!

if is visit http://www.mysite.com site work fine

if i visit mysite.com (with out the www) i get this error

Warning: Cannot modify header information – headers already sent by (output started at /home/classcar/public_html/wp-content/themes/classcar/functions.php:1) in /home/classcar/public_html/wp-includes/pluggable.php on line 899

also if it visit http://www.mysite.com/wp-admin i get this error

if i go to wp-login i get the login screen but get these errors at the top

Warning: Cannot modify header information – headers already sent by (output started at /home/classcar/public_html/wp-content/themes/classcar/functions.php:1) in /home/classcar/public_html/wp-login.php on line 409

Warning: Cannot modify header information – headers already sent by (output started at /home/classcar/public_html/wp-content/themes/classcar/functions.php:1) in /home/classcar/public_html/wp-login.php on line 421

when i enter my user name and password i get the following

ERROR: Cookies are blocked or not supported by your browser. You must enable cookies to use WordPress.

im using chrome and cookies are on.. so whats going on??

I have read the FAG on checking for ending ?> and started <?php without spaces etc and all looks fine!

whats going on!