DirectX Camera Jitter - matrix

Question

Source Code.
I'm making a small DirectX Demo Scene but my camera seems to "snap" to odd positions when I attempt to rotate it. It only happens when rotating and I can't seem to find out what is causing it.
// Get the cursor pos and calculate change in movement
POINT cursorPos;
GetCursorPos(&cursorPos);
LONG deltaX = oldCursorPos.x - cursorPos.x;
LONG deltaY = oldCursorPos.y - cursorPos.y;
// Hold right click to rotate
if (GetAsyncKeyState(VK_RBUTTON))
{
XMMATRIX xRotation = XMMatrixRotationY(((float)-deltaX * (float)timer.Delta()));
XMMATRIX yRotation = XMMatrixRotationX(((float)-deltaY * (float)timer.Delta()));
XMMATRIX view = XMLoadFloat4x4(&cameraMatrix);
XMFLOAT4 viewVector = XMFLOAT4(cameraMatrix.m[3][0], cameraMatrix.m[3][1], cameraMatrix.m[3][2], 1.0f);
for (size_t i = 0; i < 3; i++) { cameraMatrix.m[3][i] = 0.0f; }
view = view * xRotation;
view = yRotation * view;
XMStoreFloat4x4(&cameraMatrix, view);
cameraMatrix.m[3][0] = viewVector.x;
cameraMatrix.m[3][1] = viewVector.y;
cameraMatrix.m[3][2] = viewVector.z;
}
oldCursorPos = cursorPos;
Above is the code that performs the rotations to the camera matrix, below is the code I use to set the view matrix equal to the inverse of the camera matrix. Both of these operations are done every frame.
XMMATRIX camera = XMLoadFloat4x4(&cameraMatrix);
XMMATRIX view = XMMatrixInverse(NULL, camera);
XMStoreFloat4x4(&sceneMatrix.viewMatrix, view);
Both of these snippets don't seem to be the problem though, as I have triple checked my notes and this is exactly how my instructor expects it to be done. This bug happens in debug and release mode.
I put the source code in the link above if an attractive person such as yourself dare look at the rest of the code. Beware: It is a small demo application so try not to cringe at the hard-coded objects and such.

Answer 1

I'm not certain it's causing your problem, as a simple demo might have a consistent frame-rate, but you shouldn't be scaling mouse movement by a time delta.
These lines:
XMMATRIX xRotation = XMMatrixRotationY(((float)-deltaX * (float)timer.Delta()));
XMMATRIX yRotation = XMMatrixRotationX(((float)-deltaY * (float)timer.Delta()));
Should be
float fRotationSpeed = 0.01f; // Tweak this.
XMMATRIX xRotation = XMMatrixRotationY(((float)-deltaX * fRotationSpeed));
XMMATRIX yRotation = XMMatrixRotationX(((float)-deltaY * fRotationSpeed));