This is a question for support, but a setup file from previous versions may be the issue.
Check to see if there is a mgc_nse_2007.ini file in the C:\users\username directory (or another file with *nse* .ini)
This file can override the default settings. I suggest making a backup of the file and then deleteing the file so that the default preferences can be applied. Many of the settings have now been moved to DxDesigner.xml and DxDesigner.wsp, but if this file existed in the past, it's preferences may still be used.