Hi gui - I'm glad that you're liking MoI!

Flow using "projection" mode will shoot out rays from the base surface and try to intersect them with the target object, and if the rays miss or barely graze the target object you can get some strange results like you have here.

Your case there will actually have many projection rays miss because the base plane for Flow works on an entire surface, ignoring trim boundaries. You can see the underlying surface if you select your base plane and use Edit > Show pts, you'll probably see that it's a rectangular plane and the circular shape is from a trim boundary which isn't used for the Flow.

For what you're trying to do there, I'd recommend placing one box directly on to the sphere and then use Transform > Array > Circular to replicate it, that's usually the best way to make a circular pattern.

For placing the initial box, if you use Draw solid > Box > Center, and place the starting point snapped onto the Sphere using the 3D viewport, you'll be able to track along the sphere's surface normal when drawing it.

Or another way is to draw the box off to the side to start with, and then use the Transform > Orient command to reposition it.

There is some information on Orient here:
http://moi3d.com/3.0/docs/moi_command_reference8.htm#orient

And also here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=3977.2
http://moi3d.com/forum/index.php?webtag=MOI&msg=3424.13
http://moi3d.com/forum/index.php?webtag=MOI&msg=3424.14

- Michael