Hi, mclemson:
Thanks for answering. I'll try to get the screenshots an will publish them here.
A thing I've seen is that on the Parent NS, if you right-click on the filter that got replicate to the Child NS, there appears the menu "Hierarchy > Replicate now", but when I right click on any of the filters that don't get replicated, this menu does not appear.
I'll investigate this, and publish my findings in this thread.
Edit1: After looking at the XML from one of the filters that does not replicate, I can see that it includes the following line :
<itemAttributes>NoReplication</itemAttributes>
I'll clone the filter, export the filter, delete this line, and import the filter again to see what it happens.