diff --git a/dtw.cabal b/dtw.cabal
--- a/dtw.cabal
+++ b/dtw.cabal
@@ -2,7 +2,7 @@
 -- documentation, see http://haskell.org/cabal/users-guide/
 
 name:                dtw
-version:             1.0.1.0
+version:             1.0.2.0
 synopsis:            (Fast) Dynamic Time Warping
 description:         This package implements dynamic time warping as described
                      here <http://en.wikipedia.org/w/index.php?title=Dynamic_time_warping>
@@ -42,7 +42,8 @@
                        containers,
                        test-framework,
                        test-framework-quickcheck2,
-                       QuickCheck <2.8
+                       QuickCheck
   ghc-options:         -O2 -Wall
+  ghc-prof-options:    -fprof-auto -auto-all -caf-all -rtsopts
   hs-source-dirs:      src
   default-language:    Haskell2010
diff --git a/src/Data/DTW.hs b/src/Data/DTW.hs
--- a/src/Data/DTW.hs
+++ b/src/Data/DTW.hs
@@ -91,7 +91,7 @@
 type Path   = [Index]
 type Window = Set.Set Index
 
-data Result a = Result { cost :: a, path :: Path } deriving (Show,Read,Eq)
+data Result a = Result { cost :: {-# UNPACK #-} !a, path :: Path } deriving (Show,Read,Eq)
 
 
 -- | this is the naive implementation of dynamic time warping
@@ -101,14 +101,14 @@
 
 dtwNaive :: (Ord c, Fractional c, DataSet a, DataSet b)
          => (Item a -> Item b -> c) -> a -> b -> c
-dtwNaive δ as bs = go (len as - 1) (len bs - 1)
+dtwNaive δ as bs = go (len as) (len bs)
     where go 0 0 = 0
           go _ 0 = 1/0
           go 0 _ = 1/0
-          go x y = δ (ix as x) (ix bs y) + minimum [ go (x-1)  y
-                                                   , go  x    (y-1)
-                                                   , go (x-1) (y-1)
-                                                   ]
+          go x y = δ (ix as (x-1)) (ix bs (y-1)) + minimum [ go (x-1)  y
+                                                           , go  x    (y-1)
+                                                           , go (x-1) (y-1)
+                                                           ]
 
 -------------------------------------------------------------------------------------
 
@@ -128,7 +128,7 @@
                 -> a
                 -> b
                 -> Result c
-dtwMemoWindowed δ inWindow as bs = go (len as - 1) (len bs - 1)
+dtwMemoWindowed δ inWindow as bs = go (len as) (len bs)
     where -- wrap go' in a memoziation function so that each value
           -- is calculated only once
           go = vecMemo2 (len as) (len bs) go'
@@ -146,13 +146,13 @@
                                                               , go  x    (y-1)
                                                               , go (x-1) (y-1) ]
                   newPath   = (x,y) : path minResult
-                  newCost   = δ (ix as x) (ix bs y) + cost minResult
+                  newCost   = δ (ix as (x-1)) (ix bs (y-1)) + cost minResult
 
 {-# INLINABLE dtwMemoWindowed #-}
 
 vecMemo2 :: Int -> Int -> (Int -> Int -> a) -> Int -> Int -> a
-vecMemo2 w h f = \x y -> v V.! (x + y*w)
-    where v = V.generate (w*h) (\i -> let (y,x) = i `divMod` w in f x y)
+vecMemo2 w h f = \x y -> v V.! (x + y*(w+1))
+    where v = V.generate ((w+1)*(h+1)) (\i -> let (y,x) = i `divMod` (w+1) in f x y)
 
 -------------------------------------------------------------------------------------
 
diff --git a/test/MainTest.hs b/test/MainTest.hs
--- a/test/MainTest.hs
+++ b/test/MainTest.hs
@@ -70,9 +70,22 @@
 {-        costB = cost (fastDtw dist 10 sa sb)-}
 {-        matSize = fromIntegral $ S.length sa * S.length sb-}
 
+testNaiveSingleElements :: (Double,Double) -> Bool
+testNaiveSingleElements (a,b) = abs (ca - cb) < 0.0001
+    where ca = dist a b
+          cb = dtwNaive dist [a] [b]
+
+testFastSingleElements :: (Double,Double) -> Bool
+testFastSingleElements (a,b) = abs (ca - cb) < 0.0001
+    where ca = dist a b
+          cb = cost $ fastDtw dist reduceByHalf 2 (S.singleton a) (S.singleton b)
+
+
 main :: IO ()
 main = defaultMain 
      [ testProperty "dtwMemo ≡ dtwNaive" testDTWMemoVSDTWNaive
      , testProperty "fastDtw ≅ dtwNaive" testFastDTWvsDTWNaive
      {-, testProperty "fastDtw == dtwMemo"  testFastDTWvsDTWMemo-}
+     , testProperty "single element dtwNaive" testNaiveSingleElements
+     , testProperty "single element dtwFast" testFastSingleElements
      ]