Well Dave T, there is some progres now. First, cheking the anti-aliasing does make a difference, image details are more 
"real". Now I am answering from my other Lap with ViSTA, since I only had installed FS 2004 standard 
(after my last ViSTA reinstall, all my files reinstall & etcéteras reinstalls   
   
   )
 ). It's not so standard because 
Real Environment enhances it a bit, but anyway did the Copy trick & installed Golden Wings 3. Firstly I installed in a TEMP file to see what is going to be changed & try to locate the culprit for the ground textures going kaput. Then, I would let the installer do it's job & take Screen Shots for comparison.
The first thing is as allways in ViSTA: in GW no historical flights open & the Simulator just closes itself, nor any lessons are available for the same reason: GW just shuts down. So we can't compare the London to Darwin flight, had to compare the Duxford with Tante Ju flight.
After Golden Wings installed, ground textures remain good:

After installing 
Update 1, ground textures not changed yet... but lost the Taxi Ways details!! 

 :

After 
Update 2 still no changes on the ground & Taxi Ways still lost 

 :

In 
Golden Wings extras there are two Tests. After viewing 
Test 1, I noticed a BMP called DETAiL1 in Scenery/World/Textures. I backed up that file & after installing... THERE iS THE CULPRiT!! 
 
   
   
 
Its just a mater of renaming the original FS 2004 
detail1:
 YES!!!
YES!!!   
   
   
 
Before starting to mess with other texture files 
(they abound a lot, I must say) I checked GW settings. Somehow my screen resolution had changed & no anti-aliasing was checked either  
 
   
  
 Corrected & the Taxi Ways are back!! 
 
   
   
 
Then I bumped into an old view of Duxford, were the Taxi Ways are also absent: 
(I always left anti-aliasing unchecked, as per Nick instructions in the Forum). GRACiAS, DAVE T
 
  
  