Coding rules import not possible

When creating a new Profile and uploading both checkstyle.xml and pmd.xml, an error page is shown ("We're sorry, but something went wrong"). In the sonar.log the following message appears:

2008.01.31 16:04:48 ERROR rails.sonar -

ArgumentError (Could not parse object of type: <Tempfile>.):
C:/java/sonar-1.1-beta1/lib/sonar-web/WEB-INF/gems/gems/activesupport-1.4.4/lib/active_support/vendor/xml_simple.rb:191:in `xml_in'
C:/java/sonar-1.1-beta1/lib/sonar-web/WEB-INF/gems/gems/activesupport-1.4.4/lib/active_support/vendor/xml_simple.rb:203:in `xml_in'
C:/java/sonar-1.1-beta1/lib/sonar-web/app/models/rules_engines/checkstyle_engine.rb:37:in `import'
C:/java/sonar-1.1-beta1/lib/sonar-web/app/models/rules_profile.rb:79:in `import_from_xml'
C:/java/sonar-1.1-beta1/lib/sonar-web/app/controllers/rules_profile_controller.rb:50:in `create'
C:/java/sonar-1.1-beta1/lib/sonar-web/WEB-INF/gems/gems/actionpack-1.13.6/lib/action_controller/base.rb:1101:in `send'
C:/java/sonar-1.1-beta1/lib/sonar-web/WEB-INF/gems/gems/actionpack-1.13.6/lib/action_controller/base.rb:1101:in `perform_action'
C:/java/sonar-1.1-beta1/lib/sonar-web/WEB-INF/gems/gems/actionpack-1.13.6/lib/action_controller/filters.rb:696:in `call_filters'
C:/java/sonar-1.1-beta1/lib/sonar-web/WEB-INF/gems/gems/actionpack-1.13.6/lib/action_controller/filters.rb:688:in `perform_action_with_filters'
C:/java/sonar-1.1-beta1/lib/sonar-web/WEB-INF/gems/gems/actionpack-1.13.6/lib/action_controller/benchmarking.rb:66:in `perform_action_with_benchmark'
C:/java/sonar-1.1-beta1/lib/sonar-web/WEB-INF/gems/gems/actionpack-1.13.6/lib/action_controller/rescue.rb:83:in `measure'
C:/java/sonar-1.1-beta1/lib/sonar-web/WEB-INF/gems/gems/actionpack-1.13.6/lib/action_controller/benchmarking.rb:66:in `perform_action_with_benchmark'
C:/java/sonar-1.1-beta1/lib/sonar-web/WEB-INF/gems/gems/actionpack-1.13.6/lib/action_controller/rescue.rb:83:in `perform_action_with_rescue'
C:/java/sonar-1.1-beta1/lib/sonar-web/WEB-INF/gems/gems/actionpack-1.13.6/lib/action_controller/base.rb:435:in `send'
C:/java/sonar-1.1-beta1/lib/sonar-web/WEB-INF/gems/gems/actionpack-1.13.6/lib/action_controller/base.rb:435:in `process'
C:/java/sonar-1.1-beta1/lib/sonar-web/WEB-INF/gems/gems/actionpack-1.13.6/lib/action_controller/filters.rb:684:in `process_with_filters'
C:/java/sonar-1.1-beta1/lib/sonar-web/WEB-INF/gems/gems/actionpack-1.13.6/lib/action_controller/session_management.rb:114:in `process_with_session_management_support'
C:/java/sonar-1.1-beta1/lib/sonar-web/WEB-INF/gems/gems/actionpack-1.13.6/lib/action_controller/base.rb:334:in `process'
C:/java/sonar-1.1-beta1/lib/sonar-web/WEB-INF/gems/gems/rails-1.2.6/lib/dispatcher.rb:41:in `dispatch'
:1

Attached the two XML files which I tried to upload (both have been created with Sonar 1.0.2 before migrating to 1.1-beta1)
When uploading only one file, everything works fine.
Error occurs in both Firefox and Internet Explorer