Looks like we can't reproduce the issue or there's a problem in the test case provided.
Touch Premium Member
Neptune Layout Bug
Not sure if bugs are being reported on neptune as it is just a teaser, but I found an odd behavior in the docked menus example. When resizing the browser, the items docked to the sides increase in sized and never return eventually pushing the contents out of view.
Made video of it.
At this point there's still work to do on both the theme and the layout system, I'd hold off on reporting bugs until we have a beta out.
Twitter - @evantrimboli