diff --git a/src/Paket.Core/PackageAnalysis/Why.fs b/src/Paket.Core/PackageAnalysis/Why.fs
index f2c74c3415..36fc2c3767 100644
--- a/src/Paket.Core/PackageAnalysis/Why.fs
+++ b/src/Paket.Core/PackageAnalysis/Why.fs
@@ -18,15 +18,19 @@ and LblPathNode<'a> =
 | LblPathLeaf of PackageName * 'a
 
 module AdjLblGraph =
-    let rec paths start stop visited (g: AdjLblGraph<_>) : list<LblPath<_>> =
-        let adjacents = 
-            g.[start]
-            |> Seq.filter (fun kv -> not (Set.contains kv.Key visited))
-        [ for kv in adjacents do
-            let n, lbl = kv.Key, kv.Value
-            if n = stop then yield (start, LblPathLeaf (stop, lbl))
-            for path in paths n stop (Set.add n visited) g do 
-                yield (start, LblPathNode path)]
+    let paths start stop (visited:HashSet<_>) (g: AdjLblGraph<_>) : list<LblPath<_>> =
+        let rec paths start stop (g: AdjLblGraph<_>) : list<LblPath<_>> =
+            [ for kv in g.[start] do
+                match visited.Add kv.Key with
+                | false -> ()
+                | true -> 
+                    if kv.Key = stop then
+                        yield (start, LblPathLeaf (stop, kv.Value))
+
+                    for path in paths kv.Key stop g do 
+                        yield (start, LblPathNode path)]
+
+        paths start stop g
 
 let depGraph (res : PackageResolver.PackageResolution) : AdjLblGraph<_> =
     res
@@ -77,6 +81,7 @@ module DependencyChain =
                     sprintf "%s -%s%s" (formatName name (i+1)) (formatVerReq vr) (formatFxReq fr)
                 | LblPathLeaf (name,_), false -> 
                     formatName name (i+1)
+
             sprintf "%s%s%s" (formatName name i) Environment.NewLine rest
         
         format' 0 c
@@ -145,7 +150,7 @@ module Reason =
             let chains = 
                 topLevelDeps
                 |> Set.toList
-                |> List.collect (fun p -> AdjLblGraph.paths p packageName Set.empty graph)
+                |> List.collect (fun p -> AdjLblGraph.paths p packageName (HashSet<_>()) graph)
             match Set.contains packageName directDeps, Set.contains packageName topLevelDeps with
             | true, true ->
                 Result.Ok ((TopLevel, group.Resolution), [])
diff --git a/src/Paket/Paket.fsproj b/src/Paket/Paket.fsproj
index e616e324cf..2fae9ef063 100644
--- a/src/Paket/Paket.fsproj
+++ b/src/Paket/Paket.fsproj
@@ -33,9 +33,9 @@
     <StartAction>Project</StartAction>
     <StartArguments>install</StartArguments>
     <StartWorkingDirectory>C:\temp\Gu.Reactive</StartWorkingDirectory>
-    <StartArguments>restore --group Build</StartArguments>
+    <StartArguments>why ncrontab</StartArguments>
     <StartWorkingDirectory>C:\proj\Paket</StartWorkingDirectory>
-    <StartWorkingDirectory>D:\temp\repronu110\</StartWorkingDirectory>
+    <StartWorkingDirectory>D:\code\bookstore</StartWorkingDirectory>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
     <Optimize>true</Optimize>