OK well i had a go at this and i am glad to say your help was appreciated. this is what I personally found.
- changing TRUFORM in any guise made no difference what so ever.
- By setting ati_npatch to 0 fixed the problem. as a note i changed it back to 1 after and the problem did not reappear. obviously just a kick start.
The two settings that I was palying with were :
ati_npatch (0/1) def: 1
ati_subdiv (0/1/2/3) def: 2
I am curerwently playing with defaults again and no problems

looks like HL:NS just needed a kick up the bottom to get it working

cheers all for help
P.S. to say specs : ATI X850 XT using standard catalyst 5.4 drivers