hi again laszlonagy,
yeah as you can see by my screenshot that I attached i had reserved the elements, but still it was greyed out, in fact I couldn't change layer views, or preset views either... very frustrating.
I am glad to say that our IT manager has managed to resolve the problem, as it would seem to have something to do with the way that Roles were set up and assigned to each team member, and possibly a clash with our own internal IT systems.
Basically to fix it the BIM server administrator had to log in and assign each team member a role [eg architect, technician, lead architect etc.
then permissions had to be assigned to each of these roles. As project architect role was assigned to me, I now have the ability to edit and set up new materials and composites, and it seems to be behaving as one would expect in Team work.
Many thanks for all your help and suggestions, I have to say that the You Tube ArchiCAD channel is an excellent resource, as were Constructive Thinking and AppleCore who offered their time and advice. Not all BIM software packages come with this amount of support!
Okay thanks again, now we can get stuck in!