Nested E4X Operators

Scripts using nested E4X double-dot operators do not work correctly. It may result in an error message in the log file similar to:

Error: .. cannot work with instances of this class

Consider the following script:

var person = <person><name>Bob Smith</name><likes><os>Linux</os><browser>Firefox</browser><language>JavaScript</language><language>Python</language></likes></person>; 
    alert(person..likes);                             //This line of code executes correctly 
    alert(person..likes..os);                             //This line of code fails to execute

The line of code that will fail is:

alert(person..likes..os)

A workaround for this error is to replace the line of code with:

var likes = person..likes; 
alert(likes..os);