Squirrelmail / Nginx Redirect - 404 Error

Hey, i'm using the latest Squirrelmail Web- Interface,
with Debian, Nginx, Dovecot, Postfix

If i try to delete or Write a E-Mail i will be redirectet to a 404 Page because of a double URL redirect.
The URL that i'm redirected to is:

IP/squirrelmail/src/right_main.php/squirrelmail/src/right_main.php?mailbox=INBOX&startMessage=1&composenew=0&composesession=0&session=0&use_mailbox_cache=0

I guess that it is a issue witht he NGINX rewrite but wasn't able to figure it out also if tried a lot of example out there

My current NGINX Config File is (related to the howtoforge tutorial)

Code:

        location /squirrelmail {
               root /usr/share/;
               index index.php index.html index.htm;
               location ~ ^/squirrelmail/(.+\.php)$ {
                       try_files $uri =404;
                       root /usr/share/;
                       fastcgi_pass unix:/var/run/php5-fpm.sock;
                       fastcgi_index index.php;
                       fastcgi_param SCRIPT_FILENAME $request_filename;
                       include /etc/nginx/fastcgi_params;
                       fastcgi_param PATH_INFO $fastcgi_script_name;
                       fastcgi_buffer_size 128k;
                       fastcgi_buffers 256 4k;
                       fastcgi_busy_buffers_size 256k;
                       fastcgi_temp_file_write_size 256k;
                       fastcgi_intercept_errors on;
               }
               location ~* ^/squirrelmail/(.+\.(jpg|jpeg|gif|css|png|js|ico|html|xml|txt))$ {
                       root /usr/share/;
               }

        }
        location /webmail {
               rewrite ^/* /squirrelmail last;
        }