Consistent CTD on a WorldMap change has been documented before but has not been reproducible. Pass your saved files to me (zipped) at
zhugetx@yahoo.com. I'll deliver them to Steve Moret (ToEE lead programmer) if I can reproduce the bug.
If you have a series of earlier saves, that might help in figuring out at which point this bug took place. Just reload a few saves before and see if you can still travel on the WorldMap.
Hope your characters have no persistent spell effects on. Also try dismissing an NPC or two.
I also hope you have already patched with the 2nd official patch. There were quite a number of CTD problems fixed in the official patches.