Hi Richard, > Given that the mp4 module works remarkably well on the whole, where > should I look to find the cause of these rare errors? (and what do they > actually mean :)) > > nginx version: nginx/1.2.9 I would suggest you upgrade nginx. Between nginx/1.2.9 and a recent releases there are 4 bugfixes in the mp4 module. Upgrade to nginx 1.4.1. Lukas