Weird Mouse Selection Issues

[eliot15]

On my computer at home, when I hold down my left mouse botton and drag, a square selection box appears that outlines the area I am dragging over.

On my computer at work, when I hold down my left mouse botton and drag, the square selection box doesn't appear, but what I have drug over is selected nonetheless.

Can I make the selection box appear by tweaking a GibbsCAM setting, or is this just a weird mouse issue?

Thanks