Well.. you shouldn't have posted untill Monday, because now it will probably go way down the list, and maybe onto the 2nd page.
Anyways, it could be that your terrain is detail.
No wait.. actually, if you have that nomarks thing turned on, in your shader (of the terrain) that might be why. It might be thinking the blood is a "mark" so it doesn't draw it. Cut the terrain with your saber (or shoot it) and see if it leaves a mark. If not, that might be your problem (make sure wall marks is turned on in your menu)