Hi Mark,

> I also thought my model was fully joined but I don't think it is.

Just to add to this and help you find out if your model is joined and to find open/unattached edges, there is a script to highlight these 'naked' edges that you can assign a keyboard shortcut to.

script:var gd = moi.geometryDatabase; gd.deselectAll(); var breps = gd.getObjects().getBreps(); for ( var i = 0; i < breps.length; ++i ) breps.item(i).getNakedEdges().setProperty( 'selected', true );

(Note:the script is one long line)

[EDIT]:BTW this only works for V2.

Cheers
~Danny~