warning: already initialized constant ICS

[Meltemi]

trying to start Rails server and getting a "warning" I don't
understand. Anyone know what it means? I'm new to event_calendar gem
and not sure what's happening. I have no 'ICS' content in my own code
(that I'm aware of).

warning: already initialized constant ICS

Here it is in context:

meltemi$ rails s
=> Booting WEBrick
=> Rails 3.1.3 application starting in development on http://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server
/Users/meltemi/.rvm/gems/ruby-1.9.3-p0@summit/gems/actionpack-3.1.3/
lib/action_dispatch/http/mime_type.rb:101: warning: already
initialized constant ICS
[2012-01-15 12:28:34] INFO WEBrick 1.3.1
[2012-01-15 12:28:34] INFO ruby 1.9.3 (2011-10-30) [x86_64-
darwin11.2.0]
[2012-01-15 12:28:34] INFO WEBrick::HTTPServer#start: pid=61345
port=3000