http://www.colorofcrime.com/colorofcrime2005.html
Blacks are 39 times more likely to commit a violent crime against whites then vice versa, and 136 times more likely to commit a robbery.
If you assume the population is roughly 10% black (A bit low but makes for easy "back of napkin" math) you would expect black-on-white crime to happen 10 times as often. The 39 times doesnt support population distributions now does it? So why is it there is such a high degree of black on white crime and yet such a low count of hate crime charges against blacks?
The numbers dont really seem to add up to the idea blacks are disproportionately targeted with hate crime charges. But, they do help illustrate why blacks might appear to be charged at a higher rate as per your post. If blacks commit crimes against whites in the numbers I've shown then by all accounts your numbers should be vastly higher than they are, demonstrating blacks aren't charged as often as whites.