It's a spot that blows up the TDB every time I try to touch the existing track.
If the route you're working on was created using the old original GLOBAL\TSection.dat you are in dangerous territory!

The way to tell is to look at the Routes TSection.dat file. Open with Wordpad, Notepad or Context and look at the top of the file.
If it starts with SectionCurve ( 0 ) 40000 you are good to go.
However if it starts with SectionCurve ( 0 ) 376 stop editing! You are attempting to edit a route created with the default global TSection.dat file and serious damage will be done to your route. If you select a Dynamic Track section the editors will crash.

The routes local tsection.dat file MUST be re-indexed if you want to edit using the latest available track sections.
HORACE is the program that does and I think Route_Riter may also have a routine to do this.
Read the DO part of this Tutorial by Jovet.