I use Visual foxpro to program rather than VB, but I am sure that you have the similar error trapping code to mine. In Visual Foxpro I had a similar problem where one location in the route created the error message that Mappoint was unable to find driving directions to that point. I simply put in an "ON ERROR" snippet that allowed me to perform other logic when this happened. In my case, I was looking for distances between 2 points so my on error section changed the calculation of distances from the calculate command to the distance as the crow flies which is less accurate but still close enough for my purposes.
In your case, once you trap the problem with "ON ERROR" you can perhaps put in code to look for a nearby location that is calculable.
At the very least, you are not stuck in limbo.
Ralph Skrzydlo
www.technologix.ca