System Information
MacBook Pro
Processor 2.2 GHz Intel Core i7
Memory 8 GB 1333 MHz DDR3
Graphics AMD Radeon HD 6750M 1024 MB
Software OS X 10.8.5 - Mountain Lion

Blender Version
2.72b (9e963ae)

Short description of error
There seems to be a rendering inconsistency between the Material render mode and the Rendered (cycle) render mode in the viewport whenever rendering a environment texture (e.g. equilateral textured mapped to a sphere).

Exact steps for others to reproduce the error
see the attached blend file and the screenshots showing Venus texture map mapped to a sphere (the upper viewport is Material render mode, the bottom is the Rendered Mode). The correct mapping of the Venus texture is given by the Material render mode, while the Rendered (cycle) render mode seems to have a Y flip of the texture.