I use the "standardized file loader panel" with the XML loader and the example files provided with XML loader.
I guess that the bug is independent of the chosen file loader.

I first ask to load into folder aaa (say). I load simplescan.xsl (O.K.)
Then I ask to load in root. I load (again) simplescan << BUG
A new folder root is created (root:root) and the data is put inside. This is NOT what is expected.

In fact, the creation of folder aaa is not necessary. Just select "create new", and then revert to root.
this is not a TRUE bug, but this is REALLY unexpected
Francis Dalaudier