possible hacking

Hi there
Has my website been hacked?

I can’t log in. I get these messages?

Warning: Cannot modify header information – headers already sent by (output started at /home/p/r/proximity/web/public_html/wp-content/gallery/.%DC3B%B71B%2690%E3AA%F26B%A11C:445) in /home/p/r/proximity/web/public_html/wp-login.php on line 337

Warning: Cannot modify header information – headers already sent by (output started at /home/p/r/proximity/web/public_html/wp-content/gallery/.%DC3B%B71B%2690%E3AA%F26B%A11C:445) in /home/p/r/proximity/web/public_html/wp-login.php on line 349

Also I have a strange character set applied to the content. See this page and notice the tm instead of ” ‘
http://www.cfcnet.co.uk/2008/08/25/deco-delivers-as-chelsea-scrape-win/

Finally in the
wp-content/gallery folder I have dozens of these kind of file names

.%DC3B%B71B%2690%E3AA%F26B%A11C

Can anyone help?