Hey Bruno...your a champion!!!..I new you meant  X...Fancy seeing you hear..I.ve been going back and forth between the two forums hoping for an answer....

Ok..double clicked on the "underlying Material" (picture of road)..you then get material-1 picture of road, material-2 grey bumpy cylinder (chimney dirty)...I double clicked on material 1 to find its CALLED checkerboard...Oh!!..ok changed the rotation bit...NOTHING....repopulated no change...Did you actually get it to work?..the image changes direction in the material 1 preview..thats it...what have i missed?

Ivan.