diff --git a/lsyncd.c b/lsyncd.c
index 22b9d24..878640b 100644
--- a/lsyncd.c
+++ b/lsyncd.c
@@ -546,9 +546,10 @@ l_now(lua_State *L)
 /**
  * Returns (on Lua stack) the addition of a clock timer by seconds. 
  *
- * @param1 the clock timer
- * @param2 seconds to change clock.
- * TODO
+ * @param1 (Lua stack) the clock timer
+ * @param2 (Lua stack) seconds to change clock.
+ *
+ * @return (Lua stack) clock timer + seconds.
  */
 static int
 l_addtoclock(lua_State *L) 
@@ -565,6 +566,7 @@ l_addtoclock(lua_State *L)
  * 
  * @param  (Lua stack) Path to binary to call
  * @params (Lua stack) list of string as arguments
+ *
  * @return (Lua stack) the pid on success, 0 on failure.
  */
 static int
@@ -893,9 +895,10 @@ bool move_event = false;
  * Handles an inotify event.
  */
 static void 
-handle_event(lua_State *L, struct inotify_event *event) {
-	/* TODO */
-	int event_type = NONE;
+handle_event(lua_State *L, 
+             struct inotify_event *event) 
+{
+	int event_type;
 
 	/* used to execute two events in case of unmatched MOVE_FROM buffer */
 	struct inotify_event *after_buf = NULL;
@@ -1159,10 +1162,27 @@ main(int argc, char *argv[])
 
 	/* load Lua */
 	L = lua_open();
+	luaL_openlibs(L);
+	{
+		/* checks the lua version */
+		const char *version;
+		int major, minor;
+		lua_getglobal(L, "_VERSION");
+		version = luaL_checkstring(L, -1);
+		if (sscanf(version, "Lua %d.%d", &major, &minor) != 2) {
+			fprintf(stderr, "cannot parse lua library version!\n");
+			return -1; // ERRNO
+		}
+		if ((major < 5) || (major == 5 && minor < 1)) {
+			fprintf(stderr, "lua library is too old. Need 5.1 at least");
+			return -1; // ERRNO
+		}
+		lua_pop(L, 1);
+	}
 
 	{
+		/* prepares logging early */
 		int i = 1;
-		/* Prepares logging early */
 		add_logcat("Normal", LOG_NOTICE);
 		add_logcat("Error",  LOG_ERR);
 		while (i < argc) {
@@ -1180,8 +1200,7 @@ main(int argc, char *argv[])
 		}
 	}
 
-	/* TODO check lua version */
-	luaL_openlibs(L);
+	/* registers lsycnd core */
 	luaL_register(L, "lsyncd", lsyncdlib);
 	lua_setglobal(L, "lysncd");
 
@@ -1278,7 +1297,7 @@ main(int argc, char *argv[])
 	}
 
 	{
-		/* checks version match between runner/core */
+		/* asserts version match between runner and core */
 		const char *lversion;
 		lua_getglobal(L, "lsyncd_version");
 		lversion = luaL_checkstring(L, -1);
@@ -1308,7 +1327,7 @@ main(int argc, char *argv[])
 	}
 
 	{
-		/* start the option parser in lua script */
+		/* starts the option parser in lua script */
 		int idx = 1;
 		const char *s;
 		/* creates a table with all remaining argv option arguments */
@@ -1326,7 +1345,7 @@ main(int argc, char *argv[])
 		if (s) {
 			lsyncd_config_file = s_strdup(s);
 		}
-		lua_pop(L, 2); // TODO
+		lua_pop(L, 2); 
 	}
 
 	if (lsyncd_config_file) {
diff --git a/lsyncd.lua b/lsyncd.lua
index aed9119..88625d8 100644
--- a/lsyncd.lua
+++ b/lsyncd.lua
@@ -176,7 +176,8 @@ local Delay = (function()
 	-----
 	-- Creates a new delay.
 	-- 
-	-- @param TODO
+	-- @params see below
+	--
 	local function new(etype, alarm, path, path2)
 		local o = {
 			-----
@@ -445,7 +446,7 @@ local Inlet, InletControl = (function()
 	--
 	local function cancelEvent(event)
 		local delay = event[delayKey] 
-		if delay.status ~= "waiting" then
+		if delay.status ~= "wait" then
 			log("Error", "Ignored try to cancel a non-waiting event of type ",
 				event.etype)
 			return
@@ -655,9 +656,15 @@ local Sync = (function()
 			return nil
 		end
 
-		if self.delays[1] then 
-			return self.delays[1].alarm
+		-- finds the nearest delay waiting to be spawned
+		for _, d in ipairs(self.delays) do
+			if d.status == "wait" then
+				return d.alarm
+			end
 		end
+
+		-- nothing to spawn.
+		return nil
 	end
 		
 	-----
@@ -1119,10 +1126,13 @@ end)()
 --============================================================================
 
 -----
--- true after runner.initalized()
--- TODO change to string X2
+-- Current status of lsyncd.
 --
-local running = false
+-- "init"  ... on (re)init
+-- "run"   ... normal operation
+-- "fade"  ... waits for remaining processes
+--
+local lsyncdStatus = "init"
 
 ----
 -- the cores interface to the runner
@@ -1284,7 +1294,7 @@ function runner.initialize()
 	end
 
 	-- from now on use logging as configured instead of stdout/err.
-	running = true;
+	lsyncdStatus = "run";
 	lsyncd.configure("running");
 
 	-- runs through the syncs table filled by user calling directory()
@@ -1372,8 +1382,8 @@ end
 -- Main utility to create new observations.
 --
 function sync(opts)
-	if running then
-		error("Cannot add new syncs while running!")
+	if lsyncdStatus ~= "init" then
+		error("Sync can only be created on initialization.", 2)
 	end
 	Syncs.add(opts)
 end
@@ -1456,9 +1466,9 @@ local defaultRsync = {
 --   TODO make readonly
 -- 
 default = {
+
 	-----
-	-- Default action
-	-- TODO desc
+	-- Default action calls user scripts on**** functions.
 	--
 	action = function(inlet)
 		-- in case of moves getEvent returns the origin and dest of the move
@@ -1471,7 +1481,10 @@ default = {
 	end,
 
 	-----
-	-- Called if to see if two events can be collapsed 
+	-- Called to see if two events can be collapsed.
+	--
+	-- Default function uses the collapseTable.
+	--
 	-- @param event1    first event
 	-- @param event2    second event
 	-- @return -1  ... no interconnection
@@ -1541,7 +1554,7 @@ default = {
 		if type(config.onStartup) == "function" then
 			local event = inlet.createBlanketEvent()
 			local startup = config.onStartup(event)
-			if event.status == "waiting" then
+			if event.status == "wait" then
 				-- user script did not spawn anything
 				-- thus the blanket event is deleted again.
 				inlet.cancelEvent(event)