I open the Technology view of my design, then I make a design change and run the View Technology Schematic process again.
The new Technology view opens, but I cannot see the changes I have made.
The "<design>.ngc" file has been updated.
Running Clean-Up Project Files does correct the problem.
If the Technology Viewer remains open when the new run of "View Technology Schematic" is started, the Technology Viewer incorrectly caches and holds on to the original design.
At this point, you should close and open Project Navigator again to see the altered design in the viewer.
This issue has been resolved in ISE software update 11.2.