diff --git a/src/state.rs b/src/state.rs
index 346eb0d..9658d66 100644
--- a/src/state.rs
+++ b/src/state.rs
@@ -104,7 +104,7 @@ fn lw_string_format (l: &mut State, num_args: usize) -> usize {
 	assert_eq! (f_string, "%0.9f");
 	let num = l.reg (1).as_float ().unwrap ();
 	
-	let output = format! ("{}", num);
+	let output = format! ("{:0.9}", num);
 	
 	*l.reg_mut (0) = Value::from (output);
 	1
@@ -683,6 +683,8 @@ impl <'a> State <'a> {
 					for i in (offset)..(offset - 1 + b) {
 						self.registers [i] = self.registers [i + 1 + a].take ();
 					}
+					
+					self.top = popped_frame.register_offset - 1 + b - 1;
 				}
 				else {
 					// Return from the entire program
@@ -690,8 +692,9 @@ impl <'a> State <'a> {
 				}
 			},
 			Instruction::Return0 => {
-				self.stack.pop ();
+				let popped_frame = self.stack.pop ().unwrap ();
 				next_pc = self.stack.last ().unwrap ().program_counter;
+				self.top = popped_frame.register_offset - 1 + 0;
 			},
 			Instruction::Return1 (a) => {
 				let a = usize::try_from (*a).unwrap ();
@@ -715,6 +718,8 @@ impl <'a> State <'a> {
 				// Shift output register down
 				let offset = popped_frame.register_offset;
 				self.registers [offset - 1] = self.registers [offset + a].take ();
+				
+				self.top = popped_frame.register_offset - 1 + 1;
 			},
 			Instruction::SetField (a, b, c, k_flag) => {
 				let value = if *k_flag {
@@ -812,8 +817,8 @@ impl <'a> State <'a> {
 				// Skip the PC increment
 				return Ok (None);
 			},
-			Instruction::Test (a, _k) => {
-				if self.reg (*a).is_truthy() {
+			Instruction::Test (a, k) => {
+				if self.reg (*a).is_truthy() != *k {
 					next_pc += 1;
 				}
 			},
diff --git a/test_vectors/n_body_new_stuff.lua b/test_vectors/n_body_new_stuff.lua
index d8556f3..e1fd105 100644
--- a/test_vectors/n_body_new_stuff.lua
+++ b/test_vectors/n_body_new_stuff.lua
@@ -2,3 +2,6 @@ print ()
 print ("asdf")
 print (math.sqrt (16))
 print (math.sqrt (16.0))
+
+local N = tonumber (arg and arg [1]) or 1000
+print (N)