During TCK-jnlp manual testing of JDK8 on linux-x64 virtual machine I've encountered with the problem that there are no labels at all in the GUI elements. See attached virtual.jpg as an example.
It is true for JDK8 only and not reproducible with jdk6, 7. Compare with 7u6.jpg.
And this is reproducible with VMWare virtual machines created on ESXi visualization Center.
It is not reproducible if VirtualBox is used.
Not reproducible on physical systems.