Hy guys! 
I have a problem when i try brush hair on my model, and i dont know why…
I try this on 2 different OS: Windows 8.1 in Ubuntu 14
And on 2 different Blender version: 2.70 and 2.69
I’m not sure why that is happening, but you can edit out hairs individually if you go into vertex select mode.
(edit) is there a texture or vertex group controlling your emission? could be a weighting issue.
I try it… and dont work 
https://dl-web.dropbox.com/get/cap.blend?_subject_uid=171075294&w=AAC-qwhmdndQO-GcqFuHchnYNfbd0D8mzvmKfKm5SmTRxQ
Here is my head bear with hair, pls try it to find problem 
sounds like you are combing it,if some parts don’t gain any influence it must be due to having two particles.i would suggest to not use 2.70,it has some bugs .