YES!

Source/Win32/CxbxKrnl/EmuD3D8.cpp

@@ -2697,6 +2697,7 @@ static void EmuFlushD3DIVB()
 
         HRESULT hRet = g_pD3DDevice8->DrawPrimitiveUP(XTL::EmuPrimitiveType(g_dwD3DIVBPrim), XTL::EmuD3DVertex2PrimitiveCount(g_dwD3DIVBPrim, g_dwD3DIVBInd), pStreamData, i/g_dwD3DIVBInd);
 
+        // HACK: TODO: probably unnecessary!!!
         g_pD3DDevice8->Present(0,0,0,0);
 
         free(pStreamData);

Source/Win32/CxbxKrnl/EmuKrnl.cpp

@@ -589,7 +589,7 @@ XBSYSAPI EXPORTNUM(126) xboxkrnl::ULONGLONG NTAPI xboxkrnl::KeQueryPerformanceCo
 
     ::LARGE_INTEGER Counter;
 
-    QueryPerformanceFrequency(&Counter);
+    QueryPerformanceCounter(&Counter);
 
     EmuSwapFS();   // Xbox FS
 
@@ -610,6 +610,7 @@ XBSYSAPI EXPORTNUM(127) xboxkrnl::ULONGLONG NTAPI xboxkrnl::KeQueryPerformanceFr
     }
     #endif
 
+    // Xbox Performance Counter Frequency := 337F98h
     ::LARGE_INTEGER Frequency;
 
     QueryPerformanceFrequency(&Frequency);