Redmine

When trying to add a user to a group, I get a blank screen when doing it from the User screen, and nothing happens when doing it from the Group screen.

In both cases the following is logged in the production.log file:

Processing GroupsController#add_users (for 10.0.14.29 at 2010-06-08 14:56:33) [POST]
Parameters: {"commit"=>"Add", "action"=>"add_users", "authenticity_token"=>"QQrf/195gqNE9wbypF9VeVLGE8PG2WXReSJkKTNmrSQ=", "user_ids"=>["30"], "id"=>"5", "controller"=>"groups", "user_search"=>""}

ActiveRecord::RecordInvalid (Validation failed: Project can't be blank):
app/models/group.rb:38:in `user_added'
app/models/group.rb:33:in `user_added'
app/controllers/groups_controller.rb:112:in `add_users'
/usr/local/ruby-1.8.7/lib/ruby/1.8/webrick/httpserver.rb:104:in `service'
/usr/local/ruby-1.8.7/lib/ruby/1.8/webrick/httpserver.rb:65:in `run'
/usr/local/ruby-1.8.7/lib/ruby/1.8/webrick/server.rb:173:in `start_thread'
/usr/local/ruby-1.8.7/lib/ruby/1.8/webrick/server.rb:162:in `start'
/usr/local/ruby-1.8.7/lib/ruby/1.8/webrick/server.rb:162:in `start_thread'
/usr/local/ruby-1.8.7/lib/ruby/1.8/webrick/server.rb:95:in `start'
/usr/local/ruby-1.8.7/lib/ruby/1.8/webrick/server.rb:92:in `each'
/usr/local/ruby-1.8.7/lib/ruby/1.8/webrick/server.rb:92:in `start'
/usr/local/ruby-1.8.7/lib/ruby/1.8/webrick/server.rb:23:in `start'
/usr/local/ruby-1.8.7/lib/ruby/1.8/webrick/server.rb:82:in `start'

The problem seems to be with the group object, as I can add the same user to another group without issues, and other users that have no problems with their groups also do not want to be added to the problem group.

Versions:

ruby-1.8.7
rails-2.3.5
mysql-5.0.77
redmine-0.9.3.devel.3612