To duplicate:
Put multiple ships in your deployment zone.
If attempting to click-drag from the upper left to the lower right, the box is drawn and ships are selected every time.
If attempting to click-drag from the lower right to the upper left, the box is not drawn and ships are not selected.
If attempting to click-drag from the lower left to the upper right, the box is drawn but ships are not selected.
If attempting to click-drag from the upper right to the lower left, the box is drawn but ships are not selected.
Seems eminently repeatable this way on my system (Asus A8N-SLI, AMD 3800+ dual core, single BFG 7900 GTX OC, XP Pro SP2)