This site maybe help. http://skinmagonline.wordpress.com/2011/07/16/are-you-suffering-from-smelly-hair-syndrome/
Several things .. This could be related to more severe seborrheic dermatitis, a fungal infection(tinea capitis) of the scalp, or even psoriasis. It's hard to say without being able to evaluated your scalp without seeing it in person. I would encourage you, particularly if it's bothersome, to seek an in-person with your physician. Best of luck.