Dark fluff,
You convinced me to perservere with q3 and I got it working.
However I had two problems.
1 Fog causes visual problems. Turn fog on or off.
2 I got black areas where textures should be. I think it is because some textures register like an entity, so that footsteps can change according to what you are running on.
I tried just using the BLOCK textures which are for walls etc. Then I cut all the files out and put them into an empty PAK0.PK3 file.!!!!!!!!!!WORKS PERFECTLY.!!!!!!!!!!
Hope I returned the favour.