Unsetting Ubuntu/Gnome DS file type icons

Hello,

DS has been installed on a Ubuntu 10.04 64bit Lucid Lynx system (albeit after some tweaking, running Gnome). And now trying to explore how DS and DWG world works. However during the installation process some Nautilus, gvfs, file icons got messed up.

It is (of course) OK to assign the icons to *.dwg and *.dxf files (I guess that *.dwt is a DWG Template?). Seems very useful. However some other files get "standard::icon: application-vnd.dassault-systemes.draftsight-dxf, gnome-mime-application-vnd.dassault-systemes.draftsight-dxf, application-x-generic" and "standard::content-type: application/vnd.dassault-systemes.draftsight-dxf" set. This is very very annoying...

At least these files *.mon, *.res, *.dbg, *.cel, *.vrt, *.bnd are assigned Type "CAD Drawing (application/vnd.dassault-systemes.draftsight-dxf)". Which is not correct (these files have nothing to do with DS).

Where are the assignment made (during the installation process)? And above all how do I make this undone, revert back to the system defaults? I could not find it how or where the file attributes are assigned.

Thank you very much in advance.