Buddypress Group Calendar - Date Picker not loading

I am no longer seeing the date picker and the browser (Firefox 3.6.3 on Mac) error console is showing plugin specific errors - though the issue is not browser-specific. Users on various browsers, both Windows and Mac, are experiencing the issue. I am using the most recent version of the plugin.

As such, when our US users add dates into the field in MM/DD/YY format, they get unexpected results. For example a user putting today's date - 06/09/10 into the field, gets an event scheduled on September 10, 2006 - I assume because the plugin is reading YY/MM/DD.

There are several errors that are thrown regarding the plugin, but they all follow this pattern:

Warning: Error in parsing value for 'filter'. Declaration dropped.
Source File: http://mydomain.com/wp-content/plugins/bp-group-calendar/groupcalendar/datepicker/css/ui-lightness/jquery-ui-1.7.2.custom.css
Line: 18

I should note that we are loading jQuery 1.4.2 and jQuery UI 1.8.1 from Google (via the functions file) in our installation - I'm wondering if this is creating a problem, and if so, what a suggested solution might be.