WrpTool does not show P3D Outline

[Arne]

I've got an annoying error with some of my binarized P3Ds. These show up in WrpTool as a blue square with a '?' inside.
I had that issue once with one of my buildings. Couldn't force WrpTool to show the real outline. I changed something here and there with O2 and after another binarize session WrpTool suddendly showed the real outline. Neither O2 nor binarize ever gave me an error before. Now I have that issue with new buildings again.
Seems as I can't get an answer on the nekromantix forum, so I'll try here.

Are there any DOs or DON'Ts with O2 made objects when it comes to use them with WrpTool to force it to show the real outline instead of the question mark?

many thanx, Arne

[Pilot]

The blue sqare shows up when the models aren't binarized, or WRPTool can't find the models.  I know you said you binarized the models, but in my experience, binarize can be very finicky and has proven to be a bitch to work with.  Why it works some times and not others I can't tell you.

-Student Pilot