Gateway error is related to php-apc or memcache (most likely) I had those issues with 64 bit distro. It's a bug well discussed all over googleI had nginx before but ran into so much problem with the random downtime and the gateway error, for me i had hard time pinpointing the issue so i went back to apache and never looked back
yeah that the idea but if op runs several apache mods that are not threadsafe it could be bothersome as they could potentially stop workingI've not had issues with apache. The biggest issue is folks leave the pre fork mpm running and don't activate and tune the worker(multi-threaded) mpm. That and disabling unused apache modules go a long way to reducing it's memory piggishiness.
Did you compile nginx yourself ? or installed a pre-compiled (yum/apt) version ... I ran into this thing ... I wiped the server clean, reinstalled php-fpm and nginx from the repository (ubuntu) ... no problems ever sinceblandt: heh well i did the google search but most of them are generic explanation. i did try to add more worker procceser but futil had more gateways even then. Gave me a headache sigh