The following JCK 7 interactive testcases fail with GTK L&F:
api/javax_swing/interactive/JMenuTests.html#JMenu[JMenuTest0006]
api/javax_swing/interactive/JMenuTests.html#JMenu[JMenuTest0007]
api/javax_swing/interactive/JMenuTests.html#JMenu[JMenuTest0011]
api/javax_swing/interactive/JMenuTests.html#JMenu[JMenuTest0012]
api/javax_swing/interactive/JPMenuTests.html#JPMenuTests[JPMenuTests0002]

These tests instruct the user to add a separator to a menu and verify that
a separator got added. With GTK L&F on OpenSUSE, this functionality does
not appear to work (or the separator gets added but is not visible).

Screenshots that show the test frames are attached.