_d should be 1 when sending timestamp

http://support.kissmetrics.com/apis/specifications.html#recording-an-event

You're saving timeOfEvent and sending it to KM but with _d=0 that tells KM to disregard that value.
In case of an error sending the event its put back to the end of the queue which could mess events order if more events were added in the meantime...

This fix tells KM to always use the timeOfEvent regardless of when the event was sent.