The directive gzip_static does not follow the rules in gzip_types
gzip on;
gzip_static on;
gzip_http_version 1.0;
gzip_disable "MSIE [1-6]\.(?!.*SV1)";
gzip_comp_level 5;
gzip_min_length 1000;
gzip_vary on;
gzip_buffers 64 16k;
gzip_types text/plain application/xml text/css application/javascript application/x-javascript text/javascript;
#strace
open("/var/www/forum/images/smilies/attention.gif.gz", O_RDONLY|O_NONBLOCK) = -1 ENOENT (No such file or directory)
open("/var/www/forum/images/smilies/lookoutbelow.gif", O_RDONLY|O_NONBLOCK) = 319
open("/var/www/forum/images/smilies/lookoutbelow.gif.gz", O_RDONLY|O_NONBLOCK) = -1 ENOENT (No such file or directory)
open("/var/www/forum/images/smilies/heresyoursign.gif", O_RDONLY|O_NONBLOCK) = 320
open("/var/www/forum/images/smilies/heresyoursign.gif.gz", O_RDONLY|O_NONBLOCK) = -1 ENOENT (No such file or directory)
open("/var/www/forum/images/smilies/woohooo.gif", O_RDONLY|O_NONBLOCK) = 321
open("/var/www/forum/images/smilies/woohooo.gif.gz", O_RDONLY|O_NONBLOCK) = -1 ENOENT (No such file or directory)
open("/var/www/forum/images/smilies/ohno.gif", O_RDONLY|O_NONBLOCK) = 322
open("/var/www/forum/images/smilies/ohno.gif.gz", O_RDONLY|O_NONBLOCK) = -1 ENOENT (No such file or directory)
As you can see, it is looking for .gz images even though the gzip_types excludes images.