Whilst investigating a series of 502 errors I have noticed that related error messages from FastCGI stderr are being truncated and at other times the error logging seems to fail part way.

Example:
2013/02/25 09:33:14 [error] 2032#0: *29484 FastCGI sent in stderr: "o/au/com/***domain-censored***/_public/wp-includes/capabilities.php on line 1026

I came across a really old bug that I thought may have been related - http://mailman.nginx.org/pipermail/nginx-ru/2010-March/032836.html - but as I'm running 1.2.7 this patch has been implemented.

I run upwards of 60 domains on the same server and this is the only one that is having these issues. Can anyone please help me shed some light on the issue?