I don't see what the problem is. The results, in terms of the number and types of constraints, are exactly the same irrespective of the order in which you perform the trim operations. Granted, the symbols may end up being displayed in different locations, but the results are identical. If you think that this is a problem, please explain how the problem manifests itself to you and what is it that you can NOT do as a result of this behavior?
BTW, having what appeared to be previous results, in this case geometric constraints, change after an edit in some other part of the problem (sketch) is the typical behavior for any system based on the solving a simultaneous equations, which is how our Sketch constraint solver works. Every time a constraint is added, deleted or edited, the complete set of equations controlling the sketch is solved, and even if logic might say that there was NO need to change or move a constraint(s), that is not an unexpected occurrence when dealing with systems like this.
It's the last and final result that counts. What it looked like at some intermediate point in time is not relevant since Sketches, unlike feature models, are NOT solved in a timestamp order that can be rolled-back or forward at any time with the assurance that the results will not change. This is just the way it works.
And before you ask, since our 2D and 3D solvers, based on what's known as the DCM tool kits, are the most widely used constraint solvers in the CAD industry, licensed from us by virtually all of our competitors, that behavior that you're seeing in NX 5 is what you would see most anywhere else.
John R. Baker, P.E.
Product 'Evangelist'
NX Design
Siemens PLM Software Inc.
Cypress, CA
To an Engineer, the glass is twice as big as it needs to be.