REVIT EXPORT DWG - custom fill patterns

[jrf201247]

Hi everyone
I'me having a problem while exporting custom imported fill patterns to dwg.
They show all messed up (see pictures), and this is happening with several fill patterns i've created importing from .pat files, incluind the "gravel" hatch that comes up with acad.
I'me using revit 2014 and acad 2014. I've tried also exporting from a clean file (with only the roof in the pictures) and it happens the same way.
The only workround is to export in milimeters (our dwg standart is meters). Then they show allmost ok, but not perfect. But that process wil involve post-editing all dwgs, everytime we review the project, and that's allmost impossible.
Any ideas what is happening and how to fix it?thanks in advance