diff --git a/TitanEngine/TitanEngine.Debugger.Context.cpp b/TitanEngine/TitanEngine.Debugger.Context.cpp
index 390f367..bcc4084 100644
--- a/TitanEngine/TitanEngine.Debugger.Context.cpp
+++ b/TitanEngine/TitanEngine.Debugger.Context.cpp
@@ -910,35 +910,59 @@ __declspec(dllexport) bool TITCALL SetContextDataEx(HANDLE hActiveThread, DWORD
     }
     else if(IndexOfRegister == UE_MMX0)
     {
-        memcpy(&(titcontext.RegisterArea[0 * 10]), (void*) NewRegisterValue, 8);
+        int STInTopStack = GetSTInTOPStackFromStatusWord(titcontext.x87fpu.StatusWord);
+        DWORD x87r0_position = Getx87r0PositionInRegisterArea(STInTopStack);
+
+        memcpy(((uint64_t*) GetRegisterAreaOf87register(titcontext.RegisterArea, x87r0_position, 0)), (char*) NewRegisterValue, 8);
     }
     else if(IndexOfRegister == UE_MMX1)
     {
-        memcpy(&(titcontext.RegisterArea[1 * 10]), (void*) NewRegisterValue, 8);
+        int STInTopStack = GetSTInTOPStackFromStatusWord(titcontext.x87fpu.StatusWord);
+        DWORD x87r0_position = Getx87r0PositionInRegisterArea(STInTopStack);
+
+        memcpy(((uint64_t*) GetRegisterAreaOf87register(titcontext.RegisterArea, x87r0_position, 1)), (char*) NewRegisterValue, 8);
     }
     else if(IndexOfRegister == UE_MMX2)
     {
-        memcpy(&(titcontext.RegisterArea[2 * 10]), (void*) NewRegisterValue, 8);
+        int STInTopStack = GetSTInTOPStackFromStatusWord(titcontext.x87fpu.StatusWord);
+        DWORD x87r0_position = Getx87r0PositionInRegisterArea(STInTopStack);
+
+        memcpy(((uint64_t*) GetRegisterAreaOf87register(titcontext.RegisterArea, x87r0_position, 2)), (char*) NewRegisterValue, 8);
     }
     else if(IndexOfRegister == UE_MMX3)
     {
-        memcpy(&(titcontext.RegisterArea[3 * 10]), (void*) NewRegisterValue, 8);
+        int STInTopStack = GetSTInTOPStackFromStatusWord(titcontext.x87fpu.StatusWord);
+        DWORD x87r0_position = Getx87r0PositionInRegisterArea(STInTopStack);
+
+        memcpy(((uint64_t*) GetRegisterAreaOf87register(titcontext.RegisterArea, x87r0_position, 3)), (char*) NewRegisterValue, 8);
     }
     else if(IndexOfRegister == UE_MMX4)
     {
-        memcpy(&(titcontext.RegisterArea[4 * 10]), (void*) NewRegisterValue, 8);
+        int STInTopStack = GetSTInTOPStackFromStatusWord(titcontext.x87fpu.StatusWord);
+        DWORD x87r0_position = Getx87r0PositionInRegisterArea(STInTopStack);
+
+        memcpy(((uint64_t*) GetRegisterAreaOf87register(titcontext.RegisterArea, x87r0_position, 4)), (char*) NewRegisterValue, 8);
     }
     else if(IndexOfRegister == UE_MMX5)
     {
-        memcpy(&(titcontext.RegisterArea[5 * 10]), (void*) NewRegisterValue, 8);
+        int STInTopStack = GetSTInTOPStackFromStatusWord(titcontext.x87fpu.StatusWord);
+        DWORD x87r0_position = Getx87r0PositionInRegisterArea(STInTopStack);
+
+        memcpy(((uint64_t*) GetRegisterAreaOf87register(titcontext.RegisterArea, x87r0_position, 5)), (char*) NewRegisterValue, 8);
     }
     else if(IndexOfRegister == UE_MMX6)
     {
-        memcpy(&(titcontext.RegisterArea[0 * 10]), (void*) NewRegisterValue, 8);
+        int STInTopStack = GetSTInTOPStackFromStatusWord(titcontext.x87fpu.StatusWord);
+        DWORD x87r0_position = Getx87r0PositionInRegisterArea(STInTopStack);
+
+        memcpy(((uint64_t*) GetRegisterAreaOf87register(titcontext.RegisterArea, x87r0_position, 6)), (char*) NewRegisterValue, 8);
     }
     else if(IndexOfRegister == UE_MMX7)
     {
-        memcpy(&(titcontext.RegisterArea[0 * 10]), (void*) NewRegisterValue, 8);
+        int STInTopStack = GetSTInTOPStackFromStatusWord(titcontext.x87fpu.StatusWord);
+        DWORD x87r0_position = Getx87r0PositionInRegisterArea(STInTopStack);
+
+        memcpy(((uint64_t*) GetRegisterAreaOf87register(titcontext.RegisterArea, x87r0_position, 7)), (char*) NewRegisterValue, 8);
     }
     else if(IndexOfRegister == UE_x87_r0)
     {