Created attachment 37101 [details]
script & screenshot & the date captured by wireshark

I use a web server program "webtours" which is a part of loadrunner11.
the Home page of "webtours" contain some  embedded resources(*.html & *.pl & *.png),so the http samplers to this page can generate sub-samples.

1.I make a HTTP main sampler to visit this web page
2.set the Attribute "Retrieve All Embedded Resources from HTML Files" in this sampler to be "Yes".
3.put a View Results Tree into the Thread Group.
4.run the script.

Let's look into the View Results Tree,you will find there are some sub_sampler and a main sampler under the main sampler.Yes, A duplicate main sampler is under the main sampler.it does wrong sometimes! For example, the Attribute "Apply to:" of Response Assertion is set to be "sub-samples only". Fill a string "(?i)/body" which is Contained in all responses of sub-request(but not  the main_sampler) into the Attribute “Patterns to Test”. the real result is failure because the string is not found in the duplicate main sampler. is it right? I don't think so.