Operating system and graphics card
Windows 7 x64 Ultimate - GTX 580 3 Gb.
Worked: Blender 2.XX rXXXXXX ?
Short description of error
When using a texture to define density of hairs, the number of hairs displayed is about the half of what it should be.
Exact steps for others to reproduce the error
Based on a (as simple as possible) attached .blend file with minimum amount of steps
Open the .blend : there should have 50 hairs and there are about 25. Percentage of displayed particles is at 100%.