The problem was actually nothing to do with the issues in the question above - they had their Station Navigation interval set to 1' and that meant that after each edit they made, the Template Editor has to rebuild a matrix of Station Locations that is used by the Forward and Back Arrows in the Template Editor and according to development the way we are building that was not the greatest and because of the length of the job and the interval - it exposed an issue in the Corridor Model - that will be fixed today .... Hooray for development ....
Anyhow the fix was to go to Project Settings, View, Station Navigation and change that step interval to a higher number - the higher the number the faster this rebuild gets. In next release this will be fixed
Thanks to the customer for raising the issue - just goes to show if you have an issue - flag it so we can fix it and make the product better and better.
Aweome! Even Happier Modeling and Faster Production - Love It!
Alan