magazine basic header

Hi, I am using magazine basic theme and would like to add a custom header. I try to add the jpeg (also tried png) file but the following error is displayed above the logo/header on the page:

Warning: getimagesize(http://www.alineplanning.org/wp-content/themes/magazine-basic/uploads/Header Website.jpg) [function.getimagesize]: failed to open stream: HTTP request failed! HTTP/1.1 404 Not Found in /home/jlindstrom/alineplanning.org/wp-content/themes/magazine-basic/functions.php on line 91

I then ensured I have uploaed the header/logo via ftp to the folder alineplanning.org/wp-content/theme/magazine-basic/functions but still the same message appears.

Any ideas?

thanks