I'm using .dds textures and I just upgraded to 2.76. Many of the textures I'm handling have an alpha channel that must be disabled. In 2.73 there was a checkbox on the textures tab that said "use alpha". It doesn't seem to be there now. Is this a change or a bug? Also is there another way I can change the alpha option?
still on 2.76? Could something be happened to your installed copy UI somehow, using python? I re-downloaded a fresh 2.76b today from http://download.blender.org/release/Blender2.76/
and there is the option, there (here using a png image with transparency):