VLT import function : jcr_path and filter path conflict

This post is an extension of Bernard's post here:

http://help-forums.adobe.com/content/adobeforums/en/experience-manager-forum/adobe-experience-manager.topic.html/forum__zngv-hello_id_liketo.html

He marked his post 'solved', when in fact his VLT question wasn't solved - he just found a workaround with curl.

I too have a number of problems with the VLT import function, so here is a restatement of my current problem.

According to the VLT import help the import syntax is:
import -v|-s|--sysview <uri> <local-path> <jcr-path>

What is the relationship between the <jcr-path> in the command line and the path in <filter root=""/>?
Consider the following cases:

1 - Import works fine with the <jcr-path> empty and a 'normal' filter path, e.g. "/content/something/somethingelse" that represents a path in the Vault.

2 - I have found no way of usefully combining the jcr-path and the filter path.

Two absolute paths are concatenated and the import just goes around in circles.
Any kind of relative path is rejected 'java.io.IOException: Only absolute paths allowed'
Most of my experiments with the filter path lead to ' java.lang.NullPointerException: null' (e.g. empty, removing it altogether, etc.)

I want to be able to store a file structure in a vault and then insert it in the repository according to the jcr-path. Therefore, what is the relationship between these paths?

So far I have not found this point documented anywhere.

Thanks for your help.