I just updated to 2.5 and have been unable to make the calendars respond to changes on the setting page. I tend to set "ending date" and "ending time" to "0", and I hide all times from the widget list (I've tried using shortcode to change the TZ setting there, but it doesn't support it). I'm saving these settings, but end times still show up on the page. Not sure what's happening.
Once again, the install is at: http://wpamusic.com and http://wpamusic.com/tour