Thanks Maxim.

I installed nginx from the EPEL repo, I don't know of any 3rd party patches. Is it common for 3rd party patched versions to exist in a repo? Also, my current configuration has worked fine for months. I believe this problem may have started after upgrading from CentOS 5.5 to 5.6.

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nginx -V output:

nginx version: nginx/0.8.53
built by gcc 4.1.2 20080704 (Red Hat 4.1.2-48)
TLS SNI support disabled
configure arguments: --user=nginx --group=nginx --prefix=/usr/share/nginx --sbin-path=/usr/sbin/nginx --conf-path=/etc/nginx/nginx.conf --error-log-path=/var/log/nginx/error.log --http-log-path=/var/log/nginx/access.log --http-client-body-temp-path=/var/lib/nginx/tmp/client_body --http-proxy-temp-path=/var/lib/nginx/tmp/proxy --http-fastcgi-temp-path=/var/lib/nginx/tmp/fastcgi --http-uwsgi-temp-path=/var/lib/nginx/tmp/uwsgi --http-scgi-temp-path=/var/lib/nginx/tmp/scgi --pid-path=/var/run/nginx.pid --lock-path=/var/lock/subsys/nginx --with-http_ssl_module --with-http_realip_module --with-http_addition_module --with-http_xslt_module --with-http_image_filter_module --with-http_geoip_module --with-http_sub_module --with-http_dav_module --with-http_flv_module --with-http_gzip_static_module --with-http_random_index_module --with-http_secure_link_module --with-http_degradation_module --with-http_stub_status_module --with-http_perl_module --with-mail --with-file-aio --with-mail_ssl_module --with-ipv6 --with-cc-opt='-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m32 -march=i386 -mtune=generic -fasynchronous-unwind-tables' --with-cc-opt='-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m32 -march=i386 -mtune=generic -fasynchronous-unwind-tables'


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nginx -t output:

the configuration file /etc/nginx/nginx.conf syntax is ok
[emerg]: listen() to 0.0.0.0:17942, backlog 511 failed (98: Address already in use)
configuration file /etc/nginx/nginx.conf test failed



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configs

fastcgi_params
http://pastebin.com/bEYxpKhs


nginx.conf
http://pastebin.com/MX3aLQk4


phpmyadmin.conf
http://pastebin.com/UKvq4xPY


mydomain1.conf
http://pastebin.com/r96E1Nmm


mydomain2.conf
http://pastebin.com/Gku1irY1


shared_rewrite_rules
http://pastebin.com/633reaxP




Thank you for your help.