i get this error on nginx log periodically:


2009/11/20 16:37:15 [error] 65325#0: *100877 upstream prematurely closed
connection while reading response header from upstream, client:
69.63.178.251, server: XX.com, request: "POST /ping HTTP/1.1", upstream:
"fastcgi://A.B.C.D8495", host: "X.Y.Z"


nginx version: nginx/0.8.27
built by gcc 4.4.1 20090725 (Red Hat 4.4.1-2) (GCC)
configure arguments: --prefix=/opt/local --with-http_stub_status_module
--with-http_geoip_module --with-http_realip_module


how to fix this problem?
thank you!