Affect of ObjType of Connectors on LaneTo

Hi Guys

When I change the ObjType of Connectors from  1 to 2 some times it removes extra LaneTo records of the Geometry section and create a direct line (from the source shape to the target shape) and sometimes it use existing LineTo records (Connect through the points).

In both cases ConFixedCode is 3.

Anyone know how can I change ObjType to 2 WITHOUT letting visio to remove existing LaneTo rows?

Thanks

Danesh