Extending Admin PageController UI with class_eval

Hello all, I’m new to the list and to Radiant overall, so pardon me if
question is a little too basic.

I’m trying to write an extension to add a calendar capability for pages.
It’s a pretty simple extension, adding just two fields to the page
start_date and end_date. I’ve written the tag extensions and included a
calendar helper class to render a calendar of events on pages.

My last hurdle is getting the start date and end date fields to display
the page admin ui. I’ve been able to get this to work on my development
machine, which is running 0.6.1, but it doesn’t work on a remote server,
where the live site will run. The remote site is running 0.6.2.

To accomplish this addition, I’m running the following code in the
EventPageExtension::activate method:

Admin::PageController.class_eval do
before_filter :add_event_page_partials, :only => [:edit, :new]

def add_event_page_partials
    @meta ||= []
    @meta << {:field => "start_date", :type => "datetime_select", 

=> [{:include_blank => true, :order => [:month, :day, :year]}]}
@meta << {:field => “end_date”, :type => “datetime_select”,
:args =>
[{:include_blank => true, :order => [:month, :day, :year]}]}

Am I missing something? Is there some difference between 0.6.1 and
0.6.2that is causing the problem or something more nefarious? Aside
upgrading my dev environment to 0.6.2, is there anything else I can try?

Thanks in advance,