At spawn time the PLAYER_ENTERING_WORLD event is passed through to all elements to cause initialisation to occur.
The EclipseBar element does not run the UNIT_POWER function correctly due to this change: http://github.com/haste/oUF/commit/7716ec41fd6b93be352bd0b9f19ffa85bf253f47

I suggest reverting the change.

d68aaef