diff --git a/reactos/subsystems/win32/win32k/ntuser/class.c b/reactos/subsystems/win32/win32k/ntuser/class.c
index 2af4d15bc38..74c613c1a64 100644
--- a/reactos/subsystems/win32/win32k/ntuser/class.c
+++ b/reactos/subsystems/win32/win32k/ntuser/class.c
@@ -30,8 +30,8 @@
 
 #include <w32k.h>
 
-#define NDEBUG
-#include <debug.h>
+//#define YDEBUG
+#include <wine/debug.h>
 
 /* WINDOWCLASS ***************************************************************/
 
@@ -827,6 +827,9 @@ IntCreateClass(IN CONST WNDCLASSEXW* lpwcx,
     RTL_ATOM Atom;
     NTSTATUS Status = STATUS_SUCCESS;
 
+    TRACE("lpwcx=%p ClassName=%wZ MenuName=%wZ wpExtra=%p dwFlags=%08x Desktop=%p pi=%p\n",
+        lpwcx, ClassName, MenuName, wpExtra, dwFlags, Desktop, pi);
+
     if (!IntRegisterClassAtom(ClassName,
                               &Atom))
     {
@@ -2100,12 +2103,19 @@ NtUserGetClassInfo(
     pi = GetW32ProcessInfo();
     if (pi == NULL)
     {
+        ERR("GetW32ProcessInfo() returned NULL!\n");
         goto Cleanup;
     }
     _SEH_TRY
     {
         /* probe the paramters */
         CapturedClassName = ProbeForReadUnicodeString(ClassName);
+
+        if (IS_ATOM(CapturedClassName.Buffer))
+            TRACE("hInst %p atom %04X lpWndClassEx %p Ansi %d\n", hInstance, CapturedClassName.Buffer, lpWndClassEx, Ansi);
+        else
+            TRACE("hInst %p class %wZ lpWndClassEx %p Ansi %d\n", hInstance, &CapturedClassName, lpWndClassEx, Ansi);
+
         if (CapturedClassName.Length & 1)
         {
             goto InvalidParameter;
@@ -2121,6 +2131,7 @@ NtUserGetClassInfo(
         {
             if (!IS_ATOM(CapturedClassName.Buffer))
             {
+                ERR("NtUserGetClassInfo() got ClassName instead of Atom!\n");
                 goto InvalidParameter;
             }
         }
@@ -2151,7 +2162,6 @@ InvalidParameter:
             if (Ret)
             {
                 lpWndClassEx->lpszClassName = CapturedClassName.Buffer;
-
                 /* FIXME - handle Class->Desktop == NULL!!!!! */
 
                 if (Class->MenuName != NULL &&
@@ -2168,6 +2178,7 @@ InvalidParameter:
 
                 if (!(Class->Global || Class->System) && hInstance == NULL)
                 {
+                    WARN("Tried to get information of a non-existing class\n");
                     SetLastWin32Error(ERROR_CLASS_DOES_NOT_EXIST);
                     Ret = FALSE;
                 }
@@ -2175,6 +2186,7 @@ InvalidParameter:
          }
          else
          {
+            WARN("Tried to get information of a non-existing class\n");
             SetLastWin32Error(ERROR_CLASS_DOES_NOT_EXIST);
          }
     }
diff --git a/reactos/subsystems/win32/win32k/ntuser/desktop.c b/reactos/subsystems/win32/win32k/ntuser/desktop.c
index 8a83234c101..8ed84433508 100644
--- a/reactos/subsystems/win32/win32k/ntuser/desktop.c
+++ b/reactos/subsystems/win32/win32k/ntuser/desktop.c
@@ -31,8 +31,8 @@
 
 #include <w32k.h>
 
-#define NDEBUG
-#include <debug.h>
+//#define YDEBUG
+#include <wine/debug.h>
 
 static
 VOID
@@ -1694,6 +1694,8 @@ IntUnmapDesktopView(IN PDESKTOP_OBJECT DesktopObject)
     PW32HEAP_USER_MAPPING HeapMapping, *PrevLink = &PsGetCurrentProcessWin32Process()->HeapMappings.Next;
     NTSTATUS Status = STATUS_SUCCESS;
 
+    TRACE("DO %p\n");
+
     /* unmap if we're the last thread using the desktop */
     HeapMapping = *PrevLink;
     while (HeapMapping != NULL)
@@ -1756,6 +1758,7 @@ IntMapDesktopView(IN PDESKTOP_OBJECT DesktopObject)
     }
 
     /* we're the first, map the heap */
+    DPRINT("Noone mapped the desktop heap %p yet, so - map it!\n", DesktopObject->hDesktopHeap);
     Offset.QuadPart = 0;
     Status = MmMapViewOfSection(DesktopObject->DesktopHeapSection,
                                 PsGetCurrentProcess(),
@@ -1769,7 +1772,7 @@ IntMapDesktopView(IN PDESKTOP_OBJECT DesktopObject)
                                 PAGE_EXECUTE_READ); /* would prefer PAGE_READONLY, but thanks to RTL heaps... */
     if (!NT_SUCCESS(Status))
     {
-        DbgPrint("Failed to map desktop\n");
+        DPRINT1("Failed to map desktop\n");
         return Status;
     }
 
@@ -1779,6 +1782,7 @@ IntMapDesktopView(IN PDESKTOP_OBJECT DesktopObject)
     {
         MmUnmapViewOfSection(PsGetCurrentProcess(),
                              UserBase);
+        DPRINT1("UserHeapAlloc() failed!\n");
         return STATUS_NO_MEMORY;
     }
 
@@ -1786,6 +1790,7 @@ IntMapDesktopView(IN PDESKTOP_OBJECT DesktopObject)
     HeapMapping->KernelMapping = (PVOID)DesktopObject->hDesktopHeap;
     HeapMapping->UserMapping = UserBase;
     HeapMapping->Count = 1;
+    *PrevLink = HeapMapping;
 
     ObReferenceObject(DesktopObject);
 
@@ -1812,6 +1817,7 @@ IntSetThreadDesktop(IN PDESKTOP_OBJECT DesktopObject,
     NTSTATUS Status;
     BOOL MapHeap;
 
+    DPRINT("IntSetThreadDesktop() DO=%p, FOF=%d\n", DesktopObject, FreeOnFailure);
     MapHeap = (PsGetCurrentProcess() != PsInitialSystemProcess);
     W32Thread = PsGetCurrentThreadWin32Thread();