You need to delete the files WCE_B1.dat and WCE_B2.dat (not sure if .dat is the right extenstion, but the names are definately correct)
You may also have to rebuild the maps using the Map Cutter application provided with destinator PN (didn't seem to make a difference to me)
I also find that when routing, certain junctions cause CF to bomb to the desktop. This is a little less likely to happen if you mute the audio and alot less likely to happen if you have another screen selected in CF and rely on the voice prompts (audio not muted, obviously)
It's annoying, but doesn't happen so often that it becomes unuseable. Just remember to store your destination as a favourite so it's quicker to re-calculate the route when you reload after a crash.
It seems to be mainly roundabouts that cause these crashes, and since you're in the USA which generally doesn't have roundabouts, you may find it runs a lot better.
1.7 with the PN engine should sort this problem out and not need those files deleting.
You need to delete the files WCE_B1.dat and WCE_B2.dat and include the WCE.TXT from the CD, then cut the maps in Mapmonkey. Just cut something... And save, then the map will be saved in a Destinator 3 compatible format. I've had no problems with PN maps.
I'm using PN maps just for the uppgraded roads... Other than that it's still Destinator 3. So until CF 1.7 arrives or MM/Freedrive gets PN support there will not be any more map features than D3 supports.