I set up the Travelify Featured Slider with 3 posts/slides but it wouldn’t rotate through the three slides. It displayed only one of the slides with no navigation boxes or movement.
Systematically disabling plugins showed that the Wordpress Google Calendar plugin by L1 Jockeys (http://code.google.com/p/wpng-calendar/) is killing the slider on Travelify Theme.
My solution: I disabled the WPNG Calendar plugin and the slider is now rotating through the three featured image posts that I specified.
I just thought this might help others with similar plugin compatibility errors. Perhaps a fix can be found for both plugins to co-exist peacefully.