Bug adding multiple groups when starting from an empty list

[abbybader]

I verified this behavior on IE, Chrome, and Firefox.

To reproduce:

• Go to meetupgator.appspot.com
• Delete any groups already populated. URL looks like http://meetupgator.appspot.com/#groups=
• Add a group (http://www.meetup.com/Denver-Hack-Nite/). URL looks like http://meetupgator.appspot.com/#groups=&groups=Denver-Hack-Nite , and group is displayed on calendar.
• Add a second group (http://www.meetup.com/denverlamp/). URL looks like http://meetupgator.appspot.com/#groups=&groups=Denver-Hack-Nite&groups=denverlamp ... The second group displays, but the first has disappeared.

Editing the URL to http://meetupgator.appspot.com/#groups=Denver-Hack-Nite,denverlamp causes both groups to display.