This sounds like they have different settings in the DxDesigner.xml file within their \WDIR directory.
If you are both not pointing at the same \WDIR this could cause that.
You can have them adjust the settings for their fonts in xDX Designer to the same as you have in your system, or send them a copy of your DXDesigner.xml file from your \WDIR and have them place it in thiers after making a backup of their current one.
Good Luck,
Vern