Create a grid with invisible header and frozen columns - see zkfiddle

Scroll one step to the right: all columns except the frozen ones and the first not-frozen are hidden.
In my sample, the first 3 of 7 columns are frozen. Scrolling right hides columns 5,6,7. It should have hidden column 4 instead.

Scroll back to the left: the last visible not-frozen column vanishes.
In my sample, only the columns 1, 2, 3 are visible now. Columns 4 to 7 will never become visible again.

It does work correctly in ZK 6.5.5. Tested both in Chrome 36/FF 31/IE 9 on Windows 7.