ZBrushCentral

Curve tube brush is inverting the tubes...

Hi, my curve insert brush is behaving weirdly. Here it is looking fine and dandy after I have froze my subdivisions.
Sketch.png

Once I hit the ‘Freeze subdivide’ button it turns out like this:
Sketch2.png

It behaves like this everywhere on this merged subtool. If I append a sphere (or anything else) the brush behaves as normal. Any ideas/help will be gratefully received at this end.

Is this the sort of thing I can email support about or is that just needlessly annoying them?