Changing URL Fatal error

Hi Tara,
Yes I did. I first did this:
http://codex.wordpress.org/Moving_WordPress on your existing server. And afterwards I could’t login. So I checked out the file you posted and I checked out Changing the URL directly in the database and there it seemed to be correct.
For the record, my site is neither on the old location nor on the new location available. I get the same error on both.
I’m a wrack so please help!

I’m sorry for being unclear. The site is still there but I can’t excess it form either location. I get the error on both sites.

Hi Tara,

I’ve tried that but with no result. I’ve seen files go missing from the maps. What can I do?
I can see the biggest part of my site online now but still can’t login.
My current error is this:

Warning: Cannot modify header information – headers already sent by (output started at ………./wp-config.php:1) in …../wp-includes/pluggable.php on line 876

I think I’ve been hacked since there are files disapearing. I’m starting a fresh wordpress to be sure. Unfortunatly. Sad people who hack a hobby.