diff --git a/components/post.lua b/components/post.lua
index 395151f..065c3c1 100644
--- a/components/post.lua
+++ b/components/post.lua
@@ -40,10 +40,10 @@ function private.post_auction(slot, k)
 		end)
 
 		local posted
-		Aux.control.event_listener('CHAT_MSG_SYSTEM', function()
+		Aux.control.event_listener('CHAT_MSG_SYSTEM', function(kill)
 			if arg1 == ERR_AUCTION_STARTED then
 				c()
-				Aux.control.kill()
+				kill()
 			end
 		end)
 	else
diff --git a/components/scan.lua b/components/scan.lua
index 83cd206..fc28540 100644
--- a/components/scan.lua
+++ b/components/scan.lua
@@ -8,7 +8,7 @@ do
 	local scan_states = {}
 
 	function public.start(params)
-		for old_state in {scan_states[params.type]} do
+		for _, old_state in {scan_states[params.type]} do
 			m.abort(old_state.id)
 		end
 		local thread_id = Aux.control.thread(Aux.f(m.wait_for_callback, params.on_scan_start, m.scan))
@@ -215,8 +215,8 @@ end
 
 function private.wait_for_list_results(c)
     local updated, last_update
-    Aux.control.event_listener('AUCTION_ITEM_LIST_UPDATE', function()
-	    Aux.control.kill(-c)
+    Aux.control.event_listener('AUCTION_ITEM_LIST_UPDATE', function(kill)
+	    kill(-c)
         last_update = GetTime()
         updated = true
     end)
diff --git a/components/stack.lua b/components/stack.lua
index 4d78bbc..2a06305 100644
--- a/components/stack.lua
+++ b/components/stack.lua
@@ -52,7 +52,6 @@ function private.find_charge_item_slot()
 end
 
 function private.move_item(from_slot, to_slot, amount, k)
-
 	if m.locked(from_slot) or m.locked(to_slot) then
 		return Aux.control.wait(k)
 	end
@@ -80,7 +79,6 @@ function private.process()
 		m.state.target_slot = m.find_charge_item_slot()
 		return m.stop()
 	end
-
 	if m.stack_size(m.state.target_slot) > m.state.target_size then
 		local slot = m.find_item_slot(true) or m.find_empty_slot()
 		if slot then
@@ -102,24 +100,18 @@ function private.process()
 			)
 		end
 	end
-		
 	return m.stop()
 end
 
 function public.stop()
 	if m.state then
 		Aux.control.kill_thread(m.state.thread_id)
-
 		local callback, slot = m.state.callback, m.state.target_slot
 		if slot and not m.matching_item(slot) then
 			slot = nil
 		end
-		
 		m.state = nil
-		
-		if callback then
-			callback(slot)
-		end
+		Aux.safe_call(callback, slot)
 	end
 end
 
@@ -127,7 +119,6 @@ function public.start(item_key, size, callback)
 	m.stop()
 
 	local thread_id = Aux.control.thread(m.process)
-
 	m.state = {
 		thread_id = thread_id,
 		item_key = item_key,
diff --git a/control.lua b/control.lua
index 7467e1a..4be36ca 100644
--- a/control.lua
+++ b/control.lua
@@ -1,7 +1,7 @@
 local m, public, private = Aux.module'control'
 
 private.event_frame = CreateFrame('Frame')
-private.event_listeners = {}
+private.listeners = {}
 private.threads = {}
 public.thread_id = nil
 
@@ -10,34 +10,22 @@ function public.LOAD()
 	m.event_frame:SetScript('OnEvent', m.on_event)
 end
 
-do
-	local active_listener
-
-	function public.kill(...)
-		active_listener.killed = arg.n == 0 or arg[1]
-	end
-
-	function private.on_event()
-		for thread_id, listener in m.event_listeners do
-			if event == listener.event and not listener.killed then
-				m.thread_id = thread_id
-				active_listener = listener
-				listener.cb()
-				active_listener = nil
-				m.thread_id = nil
-			end
+function private.on_event()
+	for _, listener in m.listeners do
+		if event == listener.event and not listener.killed then
+			listener.cb(listener.kill)
 		end
 	end
 end
 
 function private.on_update()
-	for _, listener in m.event_listeners do
-		if not Aux.util.any(m.event_listeners, function(l) return not l.killed and l.event == listener.event end) then
+	for _, listener in m.listeners do
+		if not Aux.util.any(m.listeners, function(l) return not l.killed and l.event == listener.event end) then
 			m.event_frame:UnregisterEvent(listener.event)
 		end
 	end
 
-	m.event_listeners = Aux.util.filter(m.event_listeners, function(l) return not l.killed end)
+	m.listeners = Aux.util.filter(m.listeners, function(l) return not l.killed end)
 	m.threads = Aux.util.filter(m.threads, function(th) return not th.killed end)
 
 	for thread_id, thread in m.threads do
@@ -54,17 +42,29 @@ function private.on_update()
 	end
 end
 
+function public.kill_listener(listener_id)
+	for _, listener in {m.listeners[listener_id]} do
+		listener.killed = true
+	end
+end
+
+function public.kill_thread(thread_id)
+	for _, thread in {m.threads[thread_id]} do
+		thread.killed = true
+	end
+end
+
 function public.event_listener(event, cb)
-	local thread_id = Aux.unique()
-	m.event_listeners[thread_id] = { event=event, cb=cb }
+	local listener_id = Aux.unique()
+	m.listeners[listener_id] = { event=event, cb=cb, kill=function(...) if arg.n == 0 or arg[1] then m.kill_listener(listener_id) end end }
 	m.event_frame:RegisterEvent(event)
-	return thread_id
+	return listener_id
 end
 
 function public.on_next_event(event, callback)
-	m.event_listener(event, function()
+	m.event_listener(event, function(kill)
 		callback()
-		m.kill()
+		kill()
 	end)
 end
 
@@ -78,12 +78,6 @@ function public.thread(k, ...)
 	return thread_id
 end
 
-function public.kill_thread(thread_id)
-	if m.threads[thread_id] then
-		m.threads[thread_id].killed = true
-	end
-end
-
 function public.await(k)
 	local ret
 	m.when(function() return ret end, function() return k(unpack(ret)) end)
diff --git a/core.lua b/core.lua
index eeb94ea..27d6da8 100644
--- a/core.lua
+++ b/core.lua
@@ -295,11 +295,11 @@ do
         if money >= amount then
             locked = true
 
-            m.control.event_listener('CHAT_MSG_SYSTEM', function()
+            m.control.event_listener('CHAT_MSG_SYSTEM', function(kill)
                 if arg1 == ERR_AUCTION_BID_PLACED then
                     Aux.safe_call(on_success)
                     locked = false
-                    Aux.control.kill()
+                    kill()
                 end
             end)
         end
@@ -322,11 +322,11 @@ do
         locked = true
 
         CancelAuction(index)
-        m.control.event_listener('CHAT_MSG_SYSTEM', function()
+        m.control.event_listener('CHAT_MSG_SYSTEM', function(kill)
             if arg1 == ERR_AUCTION_REMOVED then
                 Aux.safe_call(on_success)
                 locked = false
-                Aux.control.kill()
+                kill()
             end
         end)
     end