xMenu shrinks grid

I have an xWindow, with xTabs, and in one tab I have an xMenu and an xGrid. This all worked fine in 2.0.

In 2.5 when I mouse over the xMenu, the tab contents shrink up to 1/4 the height. If I then move mouse over to a blank spot and click, contents get moved back, but slightly messed up at the grid.

The issue wasn’t reproduced locally. The sample is attached
win_tabbar.zip (166 KB)