System Information
Windows 8

Blender Version
blender 2.75a and blender 2.76RC3

Short description of error
In Texture painting, the brush soften at 0.0000001 or a 1 strength has the same effect. It works well with the sharpen mode.

Exact steps for others to reproduce the error
In texture painting mode, with the brush soften, try at 0.0000001 strength and at 1, the result is the same

http://www.pasteall.org/blend/38491
screenshot: http://www.pasteall.org/pic/show.php?id=93986

Thanks a lot !