When calling StackFrame.getArgumentValues() on a frame that corresponds to Thread.sleep(), I always get thie exception:

com.sun.jdi.InternalException: Unexpected JDWP Error: 32
        at com.sun.tools.jdi.JDWPException.toJDIException(JDWPException.java:47)
        at com.sun.tools.jdi.StackFrameImpl.getArgumentValues(StackFrameImpl.java:343)

Is it caused by the native frame?
In Javadoc of StackFrame.getArgumentValues() there is no restriction, just the frame must be valid.
Anyway, I should not get InternalException.