DGN to Filegeodb geometry problem

I am trying to convert a significant amount of 2D and 3D data from dgn into ESRI FIlegeodatabase format. Most of it is ok, but I am getting an increasing number of levels which either don't convert, or if they do simply crash ArcGIS if you try and open them. It would appear the reason is Bentley View lists the xy coordinates of features in these levels as 'Disconnect' rather that a coordinate. When you display this data Bentlry View it appears fine, but when you display it in the FME Inspector the segments just shoot off into infinity.