Your plugins doesn't have safe implementation when it comes to cron_schedules. It clears whole array just to push it own entries. This caused other plugin I've ben using to stop working.
In documentation (http://codex.wordpress.org/Plugin_API/Filter_Reference/cron_schedules) it's mentioned that "Be sure to add your schedule to the passed array, as shown in the example. If you simply return only your own schedule array then you will potentially delete schedules created by other plugins." and that's exactly what happened in my case.
Could you please fix this issue on your side so it won't repeat itself in future? Thanks for help.