SubMenu of a JMenu with no items paints a single pixel tiny menu.

This was observed on Solaris 10 OS under Metal Look And Feel with the current jdk7 b07 pit build.

1)Compile the attached test and execute it with the 7.0 bo7 pit build.
2)Click on Menu named "BuggyMenu6", the drop down appears.
3)Move the mouse down to focus on the first menu Item named "subMenu6a".
Observe the tiny painting artifact at the top right corner menuItem.

The image captured of this behavior is attached with the bug report.
This is occuring on linux systems also, but it is too small to be visible.