diff --git a/parts/ai.lua b/parts/ai.lua
index b4fbcbe9..016aa36a 100644
--- a/parts/ai.lua
+++ b/parts/ai.lua
@@ -37,24 +37,43 @@ if type(_CC)=='table'then
 	}
 	local CC=CC
 	function CC.updateField(P)
+		if not P.AI_thread then return end
 		local F,n={},1
-		for y=1,min(#P.field,40)do
+		local field=P.field
+		for y=1,min(#field,40)do
+			local sum=0
 			for x=1,10 do
-				F[n]=P.field[y][x]>0
+				if field[y][x]>0 then
+					F[n]=true
+					sum=sum+1
+				else
+					F[n]=false
+				end
 				n=n+1
 			end
+			if sum==10 then
+				--[[
+					--Print field and crash the game
+					for i=24,0,-1 do
+						local l=""for j=1,10 do l=l..(F[10*i+j]and"X"or"_")end print(l)
+					end
+					error("Row "..y.." full")
+				]]
+				P.AI_thread=nil
+				return
+			end
 		end
 		while n<=400 do
 			F[n]=false
 			n=n+1
 		end
 		if not pcall(CC.update,P.AI_bot,F,P.b2b>=100,P.combo)then
-			P.AI_bot=nil
+			P.AI_thread=nil
 		end
 	end
 	function CC.switch20G(P)
 		if not pcall(CC.destroy,P.AI_bot)then
-			P.AI_bot=nil
+			P.AI_thread=nil
 			return
 		end
 		P.AIdata._20G=true
@@ -281,20 +300,19 @@ return{
 		while true do
 			--Start thinking
 			yield()
+			if not P.AI_bot then break end
 			if not pcall(CC.think,P.AI_bot)then break end
 
 			--Poll keys
 			local success,result,dest,hold,move
 			repeat
 				yield()
+				if not P.AI_bot then break end
 				success,result,dest,hold,move=pcall(CC.getMove,P.AI_bot)
 			until not success or result==0 or result==2
 			if not success then break end
 			if result==2 then
-				while true do
-					yield()
-					ins(keys,6)
-				end
+				break
 			elseif result==0 then
 				dest[5],dest[6]=dest[1][1],dest[1][2]
 				dest[7],dest[8]=dest[2][1],dest[2][2]
diff --git a/parts/player/player.lua b/parts/player/player.lua
index 29deb1ba..6b8acbe0 100644
--- a/parts/player/player.lua
+++ b/parts/player/player.lua
@@ -257,7 +257,7 @@ function Player:garbageRelease()--Check garbage buffer and try to release them
 			break
 		end
 	end
-	if flag and self.AI_mode=='CC'and self.AI_bot then CC.updateField(self)end
+	if flag and self.AI_mode=='CC'then CC.updateField(self)end
 end
 function Player:garbageRise(color,amount,line)--Release n-lines garbage to field
 	local _
@@ -518,32 +518,45 @@ function Player:freshBlock(mode)--string mode: push/move/fresh/newBlock
 	end
 end
 function Player:lock()
-	local dest=self.AI_dest
-	local has_dest=dest~=nil
-	local CB=self.cur.bk
-	for i=1,#CB do
-		local y=self.curY+i-1
-		if not self.field[y]then self.field[y],self.visTime[y]=FREEROW.get(0),FREEROW.get(0)end
-		for j=1,#CB[1]do
-			if CB[i][j]then
-				self.field[y][self.curX+j-1]=self.cur.color
-				self.visTime[y][self.curX+j-1]=self.showTime
-				if dest then
+	if self.AI_dest then
+		local dest=self.AI_dest
+		local CB=self.cur.bk
+		for i=1,#CB do
+			local y=self.curY+i-1
+			if not self.field[y]then self.field[y],self.visTime[y]=FREEROW.get(0),FREEROW.get(0)end
+			for j=1,#CB[1]do
+				if CB[i][j]then
+					self.field[y][self.curX+j-1]=self.cur.color
+					self.visTime[y][self.curX+j-1]=self.showTime
 					local x=self.curX+j-1
-					for k=1,#dest,2 do
-						if x==dest[k]+1 and y==dest[k+1]+1 then
-							rem(dest,k)rem(dest,k)
-							goto BREAK_success
+					if dest then
+						for k=1,#dest,2 do
+							if x==dest[k]+1 and y==dest[k+1]+1 then
+								rem(dest,k)rem(dest,k)
+								goto BREAK_success
+							end
 						end
+						dest=nil
+						::BREAK_success::
 					end
-					dest=nil
-					::BREAK_success::
 				end
 			end
 		end
-	end
-	if has_dest and not dest and self.AI_mode=='CC'and self.AI_bot then
-		CC.updateField(self)
+		if not dest and self.AI_mode=='CC'then
+			CC.updateField(self)
+		end
+	else
+		local CB=self.cur.bk
+		for i=1,#CB do
+			local y=self.curY+i-1
+			if not self.field[y]then self.field[y],self.visTime[y]=FREEROW.get(0),FREEROW.get(0)end
+			for j=1,#CB[1]do
+				if CB[i][j]then
+					self.field[y][self.curX+j-1]=self.cur.color
+					self.visTime[y][self.curX+j-1]=self.showTime
+				end
+			end
+		end
 	end
 end
 
diff --git a/parts/player/update.lua b/parts/player/update.lua
index e942475c..ce88c676 100644
--- a/parts/player/update.lua
+++ b/parts/player/update.lua
@@ -187,16 +187,20 @@ function update.alive(P,dt)
 		local C=P.AI_keys
 		P.AI_delay=P.AI_delay-1
 		if not C[1]then
-			if P.AI_thread and not pcall(P.AI_thread)then
-				P.AI_thread=false
+			if P.AI_thread then
+				if not pcall(P.AI_thread)then
+					P.AI_thread=nil
+				end
+			else
+				P:act_hardDrop()
 			end
 		elseif P.AI_delay<=0 then
-			P:pressKey(C[1])P:releaseKey(C[1])
 			if P.AI_mode~='CC'or C[1]>3 then
 				P.AI_delay=P.AI_delay0*2
 			else
 				P.AI_delay=P.AI_delay0*.5
 			end
+			P:pressKey(C[1])P:releaseKey(C[1])
 			rem(C,1)
 		end
 	end