Leaflet/Leaflet — pull request #1897 by Bobboya (2013-07-24 09:11:26+00:00)
Title: WMS 1.3.0 EPSG:4326 reverse axis

WMS 1.3.0 specifies that EPSG:4326 reverse x/y axis.
Therefore the bbox should be lat/lng instead of lng/lat.

WMS 1.3.0 specification, document 06-042 sections "6.7.4 Bounding boxes" gives examples (http://www.opengeospatial.org/standards/wms).

This article details the problem http://viswaug.wordpress.com/2009/03/15/reversed-co-ordinate-axis-order-for-epsg4326-vs-crs84-when-requesting-wms-130-images/ .