Problem with nginx and mongrel

Hi Friends, I have a problem with nginx and mongrel, gives the
following error:

2007/10/22 13:00:09 [error] 25122#0: *3910 upstream timed out (110:
Connection timed out) while reading response header from upstream,
client: 190.40.196.132, server: myblog.com, URL: “/admin”, upstream:
http://127.0.0.1:5008/admin”, host: “myblog.com

I was reading lists and that mistake is typical when we have requests
that take regular time or want to upload large files, but in my case
is an application of mephisto, and i only want access to the panel
administrator.

The application is running on a VPS with Ubuntu 6.06, nginx/0.5.31,
mongrel (1.0.1), mongrel_cluster (1.0.2), Rails 1.2.3, and i have
other applications that are also running well in mephisto. The problem
is solved when restarting mongrel.

Very thanks.
Rubén.