Hi LOTRJ, thanks for reporting the bug!

I can't seem to repeat the problem over here - this combined with your description makes it pretty likely that this is a video card dependent problem.

MoI relies on your video card to draw some lines into an off-screen buffer as part of the selection process, and if your video card does not do a good job of line drawing, like if it stipples the line and leaves out pixels, etc... then it can have a negative impact on selection and behave just as you describe.

Can you please tell me which kind of video card you have on your machine?

Also, has it been a long time since you have updated the video driver on your machine? If so then you may be able to resolve this problem by updating to the latest video drivers.

- Michael