This release of Xi updates the core framework to reflect various fixes and additions from most recent themes.
– added feature order field to features
– a fresh approach to button css
– updated po file for localization
– fix for iphone safari scaling bug
– ajax category filter on gallery template. add custom field show_filter set to 1
– new option to change base font size
– a new child pages gallery template, just add parent_page as custom field and enter the id
– added date format filter to events which now defaults to WordPress settings
1.5 is a little old so you may need to just re-save widgets and theme options. Possible features too. These have had various upgrades between 1.5 and 3.0 which need you to re-save settings. I think the widgets are the first thing to try since they did got a bit of an upgrade a while back.