Redmine

Hi! I'm new on redmine and ? managed to make it work under windows 7 and sql server 2008 (express edition).
I can create projects, subprojects and issues... but... when I try to see the gantt chard I get this error:
Started GET "/projects/gts/issues/gantt" for 127.0.0.1 at 2013-03-21 10:56:00 -0300
Processing by GanttsController#show as HTML
Parameters: {"project_id"=>"gts"}
Current user: fcerrutimenn (id=5)
Rendered queries/_filters.html.erb (15.0ms)
Rendered gantts/show.html.erb within layouts/base (104.0ms)
Completed 500 Internal Server Error in 174ms
ActionView::Template::Error (can't convert Date into an exact number):
89:
90: # Width of the entire chart
91: g_width = ((@gantt.date_to - @gantt.date_from + 1) * zoom).to_i
92: @gantt.render(:top => headers_height + 8,
93: :zoom => zoom,
94: :g_width => g_width,
95: :subject_width => subject_width)
lib/redmine/helpers/gantt.rb:635:in `coordinates'
lib/redmine/helpers/gantt.rb:289:in `line_for_project'
lib/redmine/helpers/gantt.rb:211:in `render_project'
lib/redmine/helpers/gantt.rb:201:in `block in render'
app/models/project.rb:733:in `block in project_tree'
app/models/project.rb:729:in `each'
app/models/project.rb:729:in `project_tree'
lib/redmine/helpers/gantt.rb:199:in `render'
app/views/gantts/show.html.erb:92:in `_app_views_gantts_show_html_erb___1026946530_38858784'
app/controllers/gantts_controller.rb:43:in `block (2 levels) in show'
app/controllers/gantts_controller.rb:42:in `show'

Can you help me?

Another problem is tha allthough calendar shows up, issues are not showed. Any ideas?

Thanks!

Fernando Cerruti