Is there any way I can "straigten out" those normals? Qdin suggested to draw the faces doublesided, but I didn't get that to work and then he had to leave. You see, I thought it was mshex that was messing up, but it was just xsi's crosswalk! So now I'm thinking about using the crosswalk to get it to xsi, but then I need to find a way to fix the normals.

I have tried many random things, but the normals don't budge.

You should be able to reset the normals by doing this:
Select your object
press U
press ctrl+a to select all polygons
right click and select:
Extract Polygons(keep)
or
Select all polygons and go to:
Model/Modify>Poly. Mesh->Extract Polygons (Keep) and freeze the new object
or
With your object selected go to an Explorer window or just click on the Clusters button on the "Select" menu and look under your object-Polygon Mesh-Clusters, there should/might be at least one Sample Cluster that contains User_Normal Property, if you delete this cluster / or this property, the normals should reset.


http://softimage.wiki.avid.com/index.php/User_Normals

Thanks that worked, fixed the normals

And after fiddling with XSI for a day, I noticed you can also go to object > polygon mesh > clusters > node properties > xsi normals <-- and delete that.