diff --git a/Facepunch.Steamworks/Interfaces/Workshop.Item.cs b/Facepunch.Steamworks/Interfaces/Workshop.Item.cs
index 70b3a59..96eaaf7 100644
--- a/Facepunch.Steamworks/Interfaces/Workshop.Item.cs
+++ b/Facepunch.Steamworks/Interfaces/Workshop.Item.cs
@@ -58,14 +58,29 @@ namespace Facepunch.Steamworks
                 }
 
                 workshop.OnFileDownloaded += OnFileDownloaded;
+                workshop.OnItemInstalled += OnItemInstalled;
                 UpdateState();
                 Downloading = true;
             }
 
             private void OnFileDownloaded( ulong fileid, Callbacks.Result result )
             {
+
                 workshop.OnFileDownloaded -= OnFileDownloaded;
                 UpdateState();
+
+                if ( result == Callbacks.Result.OK )
+                    Downloading = false;
+            }
+
+            private void OnItemInstalled( ulong fileid )
+            {
+
+                workshop.OnItemInstalled -= OnItemInstalled;
+                UpdateState();
+
+                Downloading = false;
+                Installed = true;
             }
 
             public ulong BytesDownloaded { get { UpdateDownloadProgress(); return _BytesDownloaded; } }
@@ -110,19 +125,23 @@ namespace Facepunch.Steamworks
 
                 if ( Installed && Directory == null )
                 {
+                    Size = 0;
+                    Directory = null;
+
                     ulong sizeOnDisk;
                     string folder;
                     uint timestamp;
-                    workshop.ugc.GetItemInstallInfo( Id, out sizeOnDisk, out folder, out timestamp );
-
-                    Directory = new DirectoryInfo( folder );
-                    Size = sizeOnDisk;
-
-                    if ( !Directory.Exists )
+                    if ( workshop.ugc.GetItemInstallInfo( Id, out sizeOnDisk, out folder, out timestamp ) )
                     {
-                        Size = 0;
-                        Directory = null;
-                        Installed = false;
+                        Directory = new DirectoryInfo( folder );
+                        Size = sizeOnDisk;
+
+                        if ( !Directory.Exists )
+                        {
+                            Size = 0;
+                            Directory = null;
+                            Installed = false;
+                        }
                     }
                 }
             }
diff --git a/Facepunch.Steamworks/Interop/Callback.cs b/Facepunch.Steamworks/Interop/Callback.cs
index 8b3e6bf..c6667f8 100644
--- a/Facepunch.Steamworks/Interop/Callback.cs
+++ b/Facepunch.Steamworks/Interop/Callback.cs
@@ -89,6 +89,9 @@ namespace Facepunch.Steamworks.Interop
 
         private void OnRunCallback( IntPtr ptr )
         {
+            if ( callbackPin == null ) throw new System.Exception( "Callback wasn't pinned!" );
+            if ( vTablePtr == IntPtr.Zero ) throw new System.Exception( "vTablePtr wasn't pinned!" );
+
             T data = (T) Marshal.PtrToStructure( ptr, typeof(T) );
             Function( data );
         }
@@ -96,6 +99,7 @@ namespace Facepunch.Steamworks.Interop
 
         private int GetSize()
         {
+            Console.WriteLine( "GET SIZE CALLED" );
             throw new System.NotImplementedException();
         }
 
diff --git a/Facepunch.Steamworks/Interop/steam_api_interop.cs b/Facepunch.Steamworks/Interop/steam_api_interop.cs
index 7f6de1e..ad89eec 100644
--- a/Facepunch.Steamworks/Interop/steam_api_interop.cs
+++ b/Facepunch.Steamworks/Interop/steam_api_interop.cs
@@ -5986,14 +5986,13 @@ namespace Valve.Steamworks
             return result;
         }
 
-        static System.Text.StringBuilder StringBuffer = new System.Text.StringBuilder(1024 * 16);
-
         internal override bool GetItemInstallInfo( ulong nPublishedFileID, out ulong punSizeOnDisk, out string pchFolder, out uint punTimeStamp )
         {
             CheckIfUsable();
             punSizeOnDisk = 0;
             punTimeStamp = 0;
-            
+
+            var StringBuffer = new System.Text.StringBuilder(2048);
             bool result = NativeEntrypoints.SteamAPI_ISteamUGC_GetItemInstallInfo (m_pSteamUGC,nPublishedFileID, out punSizeOnDisk, StringBuffer, (uint)StringBuffer.Capacity, out punTimeStamp );
             pchFolder = StringBuffer.ToString();
             return result;