I want to clarify. I have to turn the UV-Mapping to the right result is achieved?
When you originally bake your normal map (or create it from a gray-scale image in other application), commonly the green channel go up-down, and the red channel left-right (at least you specify differently in that application).
After that, I would recommend you compress it using the Compressonator: 1.- create the mipmaps, 2.- compress it as "ATI2N (Alternate XY Suizzle)" which will swap the green and red channels (now green will go right-left, and red up-down), and 3.- save the compressed version. The final file wont have alpha channel (yours have it), wich is not necessary and just increase the file size.
After all this you still could have a small issue with the green channel inverted; in that case, you can just select this channel in photoshop (in your uncompressed image) and invert it... Then you go to the Compressonator process again...
The most important thing here is to take care each channel go in one, and only in one direction.
Hope this help.