More Dereferencing

code/modules/mob/login.dm

@@ -30,7 +30,9 @@
 
 	client.images = null				//remove the images such as AIs being unable to see runes
 	client.screen = list()				//remove hud items just in case
-	if(hud_used)	qdel(hud_used)		//remove the hud objects
+	if(hud_used)
+		qdel(hud_used)		//remove the hud objects
+		hud_used = null
 	hud_used = new /datum/hud(src)
 
 	next_move = 1

code/modules/mob/mob.dm

@@ -3,6 +3,7 @@
 	dead_mob_list -= src
 	living_mob_list -= src
 	qdel(hud_used)
+	hud_used = null
 	if(mind && mind.current == src)
 		spellremove(src)
 	ghostize()