Comment # 3 on bug 959024 from Garrett Treaty

I am also experiencing this bug, as described by S.B.

To clarify, the 'Main MATE Menu' and 'Menu Bar' function normally. Only the
'Advanced MATE Menu' leaves a single white pixel when dragged to the panel.
Adding it to a new panel results in the same effect. 

The white pixel can only be removed by deleting the entire panel.