diff --git a/Fluent.Ribbon/Fluent.Ribbon.NET 4.0.csproj b/Fluent.Ribbon/Fluent.Ribbon.NET 4.0.csproj
index efa71ee8c..ce29a67c1 100644
--- a/Fluent.Ribbon/Fluent.Ribbon.NET 4.0.csproj	
+++ b/Fluent.Ribbon/Fluent.Ribbon.NET 4.0.csproj	
@@ -94,6 +94,7 @@
     <Compile Include="IHeaderedControl.cs" />
     <Compile Include="Internal\FocusWrapper.cs" />
     <Compile Include="Internal\ItemsControlHelper.cs" />
+    <Compile Include="Internal\KeyEventUtility.cs" />
     <Compile Include="Internal\UIHelper.cs" />
     <Compile Include="Services\ContextMenuService.cs" />
     <Compile Include="Converters\ApplicationMenuRightContentExtractorConverter.cs" />
diff --git a/Fluent.Ribbon/Fluent.Ribbon.NET 4.5.csproj b/Fluent.Ribbon/Fluent.Ribbon.NET 4.5.csproj
index 2749a737c..e69c5c5fa 100644
--- a/Fluent.Ribbon/Fluent.Ribbon.NET 4.5.csproj	
+++ b/Fluent.Ribbon/Fluent.Ribbon.NET 4.5.csproj	
@@ -94,6 +94,7 @@
     <Compile Include="IHeaderedControl.cs" />
     <Compile Include="Internal\FocusWrapper.cs" />
     <Compile Include="Internal\ItemsControlHelper.cs" />
+    <Compile Include="Internal\KeyEventUtility.cs" />
     <Compile Include="Internal\UIHelper.cs" />
     <Compile Include="Services\ContextMenuService.cs" />
     <Compile Include="Converters\ApplicationMenuRightContentExtractorConverter.cs" />
diff --git a/Fluent.Ribbon/Internal/KeyEventUtility.cs b/Fluent.Ribbon/Internal/KeyEventUtility.cs
new file mode 100644
index 000000000..e84e023c5
--- /dev/null
+++ b/Fluent.Ribbon/Internal/KeyEventUtility.cs
@@ -0,0 +1,34 @@
+namespace Fluent.Internal
+{
+    using System.Windows.Input;
+
+    internal static class KeyEventUtility
+    {
+        public static string GetStringFromKey(Key key)
+        {
+            var keyboardState = new byte[256];
+            if (NativeMethods.GetKeyboardState(keyboardState) == false)
+            {
+                return null;
+            }
+
+            var virtualKey = KeyInterop.VirtualKeyFromKey(key);
+            var scanCode = NativeMethods.MapVirtualKey((uint)virtualKey, NativeMethods.MapType.MAPVK_VK_TO_VSC);
+            var chars = new char[1];
+
+            var result = NativeMethods.ToUnicode((uint)virtualKey, scanCode, keyboardState, chars, chars.Length, 0);
+            switch (result)
+            {
+                case -1:
+                case 0:
+                    return null;
+
+                case 1:
+                    return chars[0].ToString();
+
+                default:
+                    return null;
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/Fluent.Ribbon/Internal/NativeMethods.cs b/Fluent.Ribbon/Internal/NativeMethods.cs
index 0187f8485..b99c006f8 100644
--- a/Fluent.Ribbon/Internal/NativeMethods.cs
+++ b/Fluent.Ribbon/Internal/NativeMethods.cs
@@ -236,6 +236,25 @@ public static bool _ModifyStyle(this IntPtr _hwnd, WS removeStyle, WS addStyle)
             return true;
         }
 
+        [DllImport("user32.dll", CharSet = CharSet.Unicode)]
+        internal static extern int ToUnicode(uint virtualKey, uint scanCode, byte[] keyStates, [MarshalAs(UnmanagedType.LPArray)] [Out] char[] chars, int charMaxCount, uint flags);
+
+        [DllImport("user32.dll")]
+        internal static extern bool GetKeyboardState(byte[] lpKeyState);
+
+        [DllImport("user32.dll")]
+        internal static extern uint MapVirtualKey(uint uCode, MapType uMapType);
+
+        // ReSharper disable InconsistentNaming
+        internal enum MapType : uint
+        {
+            MAPVK_VK_TO_VSC = 0x0,
+            MAPVK_VSC_TO_VK = 0x1,
+            MAPVK_VK_TO_CHAR = 0x2,
+            MAPVK_VSC_TO_VK_EX = 0x3,
+        }
+        // ReSharper restore InconsistentNaming
+
         /// <summary>
         /// GetWindowLong values, GWL_*
         /// </summary>
diff --git a/Fluent.Ribbon/Services/KeyTipService.cs b/Fluent.Ribbon/Services/KeyTipService.cs
index d175c8b06..16005528e 100644
--- a/Fluent.Ribbon/Services/KeyTipService.cs
+++ b/Fluent.Ribbon/Services/KeyTipService.cs
@@ -36,7 +36,6 @@ internal class KeyTipService
         // Attached HWND source
         private HwndSource attachedHwndSource;
 
-        private static readonly KeyConverter keyConverter = new KeyConverter();
         private string currentUserInput;
 
         /// <summary>
@@ -171,13 +170,15 @@ private IntPtr WindowProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, re
 
         private void OnWindowPreviewKeyDown(object sender, KeyEventArgs e)
         {
-            if (e.IsRepeat)
+            if (e.IsRepeat
+                || e.Handled)
             {
                 return;
             }
 
             if (this.ribbon.IsCollapsed
-                || this.ribbon.IsEnabled == false)
+                || this.ribbon.IsEnabled == false
+                || this.window.IsActive == false)
             {
                 return;
             }
@@ -224,7 +225,9 @@ private void OnWindowPreviewKeyDown(object sender, KeyEventArgs e)
                 }
 
                 var actualKey = e.Key == Key.System ? e.SystemKey : e.Key;
-                var isKeyRealInput = ((actualKey >= Key.A && actualKey <= Key.Z) || (actualKey >= Key.D0 && actualKey <= Key.D9) || (actualKey >= Key.NumPad0 && actualKey <= Key.NumPad9));
+                // we need to get the real string input for the key because of keys like ä,ö,ü #258
+                var key = KeyEventUtility.GetStringFromKey(actualKey);
+                var isKeyRealInput = string.IsNullOrEmpty(key) == false;
 
                 // Don't do anything and let WPF handle the rest
                 if (isKeyRealInput == false)
@@ -240,12 +243,15 @@ private void OnWindowPreviewKeyDown(object sender, KeyEventArgs e)
                     return;
                 }
 
+                var shownImmediately = false;
+
                 // Should we show the keytips and immediately react to key?
                 if (this.activeAdornerChain == null
                     || this.activeAdornerChain.IsAdornerChainAlive == false
                     || this.activeAdornerChain.AreAnyKeyTipsVisible == false)
                 {
                     this.ShowImmediatly();
+                    shownImmediately = true;
                 }
 
                 if (this.activeAdornerChain == null)
@@ -254,11 +260,18 @@ private void OnWindowPreviewKeyDown(object sender, KeyEventArgs e)
                 }
 
                 var previousInput = this.currentUserInput;
-                this.currentUserInput += keyConverter.ConvertToString(actualKey);
+                this.currentUserInput += key;
 
-                // If no key tips match the current input, continue with the previously entered and still correct keys.
                 if (this.activeAdornerChain.ActiveKeyTipAdorner.ContainsKeyTipStartingWith(this.currentUserInput) == false)
                 {
+                    // Handles access-keys #258
+                    if (shownImmediately)
+                    {
+                        this.activeAdornerChain?.Terminate();
+                        return;
+                    }
+
+                    // If no key tips match the current input, continue with the previously entered and still correct keys.
                     this.currentUserInput = previousInput;
                     System.Media.SystemSounds.Beep.Play();
                     e.Handled = true;
@@ -282,8 +295,10 @@ private void OnWindowPreviewKeyDown(object sender, KeyEventArgs e)
         private void OnWindowKeyUp(object sender, KeyEventArgs e)
         {
             if (this.ribbon.IsCollapsed
-                || this.ribbon.IsEnabled == false)
+                || this.ribbon.IsEnabled == false
+                || this.window.IsActive == false)
             {
+                this.activeAdornerChain?.Terminate();
                 return;
             }