Can't generate certificate for puppet-dashboard

I can't generate the cert for use with puppet-dashboard. The dashboard is running on the same host as the puppet-master, both of which are running under apache/passenger. The servername is "mon1", but "puppet" and "dashboard" are aliases for this server, and is what the various nodes use.

Versions:

puppet --version
3.2.0-rc1

puppet-dashboard:
1.2.23

The puppet name itself is resolvable:

$ curl -k https://puppet:8140
can't convert nil into String

This is my configuraiton, and below is the error:

# config/settings.yml
cn_name: 'dashboard'
ca_crl_path: 'certs/dashboard.ca_crl.pem'
ca_certificate_path: 'certs/dashboard.ca_cert.pem'
certificate_path: 'certs/dashboard.cert.pem'
private_key_path: 'certs/dashboard.private_key.pem'
public_key_path: 'certs/dashboard.public_key.pem'
ca_server: 'puppet'
ca_port: 8140

# auth.conf
path /facts
auth any
method find, search
allow *

path /inventory
auth any
method find, search
allow *

And the error:

[root@mon1 puppet-dashboard]# sudo -u puppet-dashboard rake cert:create_key_pair
DEPRECATION WARNING: Rake tasks in vendor/plugins/delayed_job/tasks are deprecated. Use lib/tasks instead. (called from /usr/share/puppet-dashboard/vendor/rails/railties/lib/tasks/rails.rb:10)
[root@mon1 puppet-dashboard]# sudo -u puppet-dashboard rake cert:request --trace
DEPRECATION WARNING: Rake tasks in vendor/plugins/delayed_job/tasks are deprecated. Use lib/tasks instead. (called from /usr/share/puppet-dashboard/vendor/rails/railties/lib/tasks/rails.rb:10)
** Invoke cert:request (first_time)
** Invoke environment (first_time)
** Execute environment
** Execute cert:request
rake aborted!
400 ""
/usr/lib/ruby/1.8/net/http.rb:2105:in `error!'
/usr/share/puppet-dashboard/lib/puppet_https.rb:27:in `put'
/usr/share/puppet-dashboard/lib/tasks/install.rake:50
/usr/lib/ruby/gems/1.8/gems/rake-10.0.4/lib/rake/task.rb:246:in `call'
/usr/lib/ruby/gems/1.8/gems/rake-10.0.4/lib/rake/task.rb:246:in `execute'
/usr/lib/ruby/gems/1.8/gems/rake-10.0.4/lib/rake/task.rb:241:in `each'
/usr/lib/ruby/gems/1.8/gems/rake-10.0.4/lib/rake/task.rb:241:in `execute'
/usr/lib/ruby/gems/1.8/gems/rake-10.0.4/lib/rake/task.rb:184:in `invoke_with_call_chain'
/usr/lib/ruby/1.8/monitor.rb:242:in `synchronize'
/usr/lib/ruby/gems/1.8/gems/rake-10.0.4/lib/rake/task.rb:177:in `invoke_with_call_chain'
/usr/lib/ruby/gems/1.8/gems/rake-10.0.4/lib/rake/task.rb:170:in `invoke'
/usr/lib/ruby/gems/1.8/gems/rake-10.0.4/lib/rake/application.rb:143:in `invoke_task'
/usr/lib/ruby/gems/1.8/gems/rake-10.0.4/lib/rake/application.rb:101:in `top_level'
/usr/lib/ruby/gems/1.8/gems/rake-10.0.4/lib/rake/application.rb:101:in `each'
/usr/lib/ruby/gems/1.8/gems/rake-10.0.4/lib/rake/application.rb:101:in `top_level'
/usr/lib/ruby/gems/1.8/gems/rake-10.0.4/lib/rake/application.rb:110:in `run_with_threads'
/usr/lib/ruby/gems/1.8/gems/rake-10.0.4/lib/rake/application.rb:95:in `top_level'
/usr/lib/ruby/gems/1.8/gems/rake-10.0.4/lib/rake/application.rb:73:in `run'
/usr/lib/ruby/gems/1.8/gems/rake-10.0.4/lib/rake/application.rb:160:in `standard_exception_handling'
/usr/lib/ruby/gems/1.8/gems/rake-10.0.4/lib/rake/application.rb:70:in `run'
/usr/lib/ruby/gems/1.8/gems/rake-10.0.4/bin/rake:33
/usr/bin/rake:19:in `load'
/usr/bin/rake:19
Tasks: TOP => cert:request

Edit:

It appears something is wrong with my apache vhost. Queries to the inventory service work when running the puppet master as a daemon or locally, but not when hosted by apache. Below is my vhost:

Listen 8140
<VirtualHost *:8140>
    SSLEngine On

    # Only allow high security cryptography. Alter if needed for compatibility.
    SSLProtocol             All -SSLv2
    SSLCipherSuite          HIGH:!ADH:RC4+RSA:-MEDIUM:-LOW:-EXP
    SSLCertificateFile      /var/lib/puppet/ssl/certs/mon1.domain.com.pem
    SSLCertificateKeyFile   /var/lib/puppet/ssl/private_keys/mon1.domain.com.pem
    SSLCertificateChainFile /var/lib/puppet/ssl/ca/ca_crt.pem
    SSLCACertificateFile    /var/lib/puppet/ssl/ca/ca_crt.pem
    SSLCARevocationFile     /var/lib/puppet/ssl/ca/ca_crl.pem
    SSLVerifyClient         optional
    SSLVerifyDepth          1
    SSLOptions              +StdEnvVars +ExportCertData

    # These request headers are used to pass the client certificate
    # authentication information on to the puppet master process
    RequestHeader set X-SSL-Subject %{SSL_CLIENT_S_DN}e
    RequestHeader set X-Client-DN %{SSL_CLIENT_S_DN}e
    RequestHeader set X-Client-Verify %{SSL_CLIENT_VERIFY}e
    DocumentRoot /usr/share/puppet/rack/puppetmasterd/public/
    <Directory /usr/share/puppet/rack/puppetmasterd/>
        Options None
        AllowOverride None
        Order Allow,Deny
        Allow from All
    </Directory>
</VirtualHost>

The Passenger related tuning settings are in a different vhost, but I don't believe they are relevant. Could this have something to do with the certificate name being "mon1.domain.com" rather than "puppet.domain.com" ?

This is an example of the access_log:

# curl -k -H "Accept: yaml" https://puppet:8140/production/facts/my.node.com
<LOCALIP> - - [09/May/2013:16:52:40 +1000] "GET /production/facts/my.node.com HTTP/1.1" 400 29 "-" "curl/7.19.7 (x86_64-redhat-linux-gnu) libcurl/7.19.7 NSS/3.14.0.0 zlib/1.2.3 libidn/1.18 libssh2/1.4.2"

# some node making a request
<REMOTEIP> - - [09/May/2013:16:52:53 +1000] "GET /production/node/some.other.node? HTTP/1.1" 200 3291 "-" "Ruby"

Note that I'm attempting to use curl from the local machine to query the facts and nodes, but that isn't working. The same as what puppet-dashboard is attempting.