Hi Rudl, it could be that you've got 2 objects stacked directly on top of one another in that spot, when 2 objects are existing in the exact same overlapping surface area that can cause things like you're describing.

Also if you have recently adjusted your video driver settings to turn anti-aliasing on, that can cause problems with the selection mechanism in MoI, so if you've done that recently switch that back to "application controlled" to avoid selection problems.

If neither of those is the case could you please post the model file or e-mail it to me at moi@moi3d.com so I can take a look?

- Michael