Yeah, that's an issue with the texture mapping on the 3D model. The 3D model itself is just a moon that someone put together, and has some flaws. I wound up building my own model (actually multiple sphere "sections" to match the fisheye on the cameras I have, with one 3D Player per camera input).
If you need a better model, it's super simple to put a sphere together in Blender - this tutorial is probably the best since the world map is basically the same equirectangular projection as your standard 360 video, although I used this one as a reference to learn how to make my sphere sections (and I really like the guy).
You will need to include an image and a UV texture map - Isadora needs that to know how to map your input (you can see that both above tutorials would give you a sphere, but with very different ways of mapping an image). You could use the world map for this (as is in the second tutorial), or put in your own image. I put my own in since, if you disconnect video input from the 3D Player, it reverts to this as the texture - so that gave me something I could use to test even w/out video input (or could be a useful "no signal" splash).