Redmine

Hello I am running Redmine using the latest
Bitnami stack on Mysql and Ubuntu.

I configured a project with a Subversion repostitory
and executed the script to fetch data into mysql db.

Redmine works fine and at the very beginning I can even open the Repository tab and see the Repository tree.
After browsing the repository or selecting the "differences" link,
Redmine stops responding (forever).
I have to kill the mongrel process (not responding properly to the stop command).

_After a long time I get the folloqing error:
Proxy Error

The proxy server received an invalid response from an upstream server.
The proxy server could not handle the request GET /redmine/projects/develenv/repository/revisions/23091/diff.

Reason: Error reading from remote server_

Note:
I have tried both with mongrel and with webrick: same behaviour.

This is the result of a ps command execution like the following:
root 26296 1 0 10:28 ? 00:00:08 /opt/redmine-0.9.2-0/ruby/bin/.ruby.bin /opt/redmine-0.9.2-0/ruby/bin/mongrel_rails start -d -e production --prefix /redmine -p 3001 -P tmp/pids/mongrel.3001.pid -l log/mongrel.3001.log
root 26312 1 1 10:28 ? 00:00:17 /opt/redmine-0.9.2-0/ruby/bin/.ruby.bin /opt/redmine-0.9.2-0/ruby/bin/mongrel_rails start -d -e production --prefix /redmine -p 3002 -P tmp/pids/mongrel.3002.pid -l log/mongrel.3002.log
root 26343 26296 0 10:30 ? 00:00:00 /opt/redmine-0.9.2-0/ruby/bin/.ruby.bin /opt/redmine-0.9.2-0/ruby/bin/mongrel_rails start -d -e production --prefix /redmine -p 3001 -P tmp/pids/mongrel.3001.pid -l log/mongrel.3001.log
root 26364 26312 0 10:32 ? 00:00:00 /opt/redmine-0.9.2-0/ruby/bin/.ruby.bin /opt/redmine-0.9.2-0/ruby/bin/mongrel_rails start -d -e production --prefix /redmine -p 3002 -P tmp/pids/mongrel.3002.pid -l log/mongrel.3002.log
root 26387 26241 0 10:47 pts/2 00:00:00 grep mongrel

There are four mongrel processes (instead of the expected two), and redmine is not responding any more..