Messed Response Stream

[Yaoxing]

Hello everyone,
I started to use nginx about 3 month ago as a reverse proxy. I met a
serious issue days ago. Some users reported that they went into other
ones' account pages unexpectly. After series of testing, I'm sure that
this happens in nginx side. Here are some tips of how to reproduce this bug:
1. The site must be under very heavy stress. Especially when there are a
lot of 502 bad gateway happening.
2. The requests must be from a remote position. we can not reproduce
this bug in intranet, I guess it's because of the network speed.
3. Access a page that is different for different users, the issues would
happen randomly.
I'm sure it's not because of proxy cache, because it only happens under
heavy stress. And if I expose IIS directly to the users, it doesn't
happen anymore.
I'm not a C/C++ programmer, but it seems to me that the memory that is
used to store one user's response stream is reused by another instance,
but actually the current instance is not finished yet. This way I can
explain why this doesn't happen in intranet. Because it's too fast.

Is there anyone else who encountered the same problem? Or is this bug
reported already?
Almost forget, I'm using nginx/0.7.64 on centos 5.
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Regards,
Yaoxing