Looks like bugs
Am 15.10.2014 00:46, schrieb hbelusca(a)svn.reactos.org:
  Author: hbelusca
 Date: Tue Oct 14 22:46:40 2014
 New Revision: 64747
 URL: 
http://svn.reactos.org/svn/reactos?rev=64747&view=rev
 Log:
 [NTVDM]: Zero-fill memory with RtlZeroMemory (that exists also in NT mode), and use
sizeof(object) instead of sizeof(type_of_object). 
 
        /* Clear the current directory buffer */
 -    ZeroMemory(CurrentDirectories, sizeof(CurrentDirectories));
 +    RtlZeroMemory(CurrentDirectories, sizeof(CurrentDirectories)); 
> @@ -2901,7 +2901,7 @@
>       WCHAR Buffer[256];
>
        /* Clear the current directory buffer */
 -    ZeroMemory(CurrentDirectories, sizeof(CurrentDirectories));
 +    RtlZeroMemory(CurrentDirectories, sizeof(CurrentDirectories)); 
  @@ -1901,7 +1901,7 @@
   VOID VgaClearMemory(VOID)
   {
 -    ZeroMemory(VgaMemory, sizeof(VgaMemory));
 +    RtlZeroMemory(VgaMemory, sizeof(VgaMemory));
   }