64 bit Win 7 home, here, but if you guys are on Win 7 64 bit then it's not Windows giving me problems.
At first it warned of resolution issues, which I fixed by changing the windowed-mode window size and the font size. The real rock in my shoe is that when something in the Incursion window should change (character movement, selecting a different menu/option), it either does not change at all or only changes in part. Often it will continue to display image and text from windows in the background after loading. The top half of the window seems to be the most prone to failure, while the bottom-left quarter is mostly accurate to the selections, other than some leftover text at the end from the previous selection. The bottom-right quarter does what it wants.
The updated text does appear if I click and drag the Incursion window, but that only makes the window display correctly for the situation rather than fix the problem. I can provide screenshots if it helps, but I wonder now whether it might just be hardware, since it works fine with your operating systems. I had similar issues on my old laptop, but got around them by making sure I was plugged in with high performance power options set during play. That does not help here, and neither does any combination of power options or plugged-in status.
Maybe it is just the hardware.