duplicate object while moving it fails to store move in undo history

[Formerly Kevin Yin, now disabled]

Open the undo history.

To reproduce:
1. draw a rectangle
2. click on the rectangle, and hold down and drag the rectangle. Don't let go of the left mouse button.
3. without letting go of the mouse button, press Ctrl D.
4. now let go of the left mouse button.

Undo history will show:
[Unchanged]
Create rectangle
Duplicate

with no mention of the move you just did.

[su_v (suv-lp)]

Reproduced with Inkscape 0.48.5 r10040 and 0.91pre2 r13530 on OS X 10.7.5.