Zip, condsider yourself excused.
Ok, Pantera, I tried your suggestions. I see what you mean now about the settings in the Surface Inspector changing. I had the alpha channel thing set but on reload it has disappeared.
I tried texturing a brush both top and bottom with the deckgrate_set1 texture and it looks ok when viewed from both sides. So for some reason even though cull is set to NONE it is only drawing the texture on one side.
Unfortunately if I do not change the surface properties of the texture I cannot shoot through it (this is one of the first problems I came across when starting mapping a few months ago and it's STILL coming back to haunt me).
I've yet to try building a new brush and doing as you said with the nodraw but as that is how I made the brushes originally I do not think it will make a difference. But I'll try it later.
Random, I have taken some screenies and if I don't sort this out soon I will try and get them published for you. (Only haven't done so far coz I'm an internet noob when it comes to things like that).
Mapping is just INCREDIBLY time consuming.