Thanks Mathew,
There is no problem with the script and applies to any use of the poly command, try this for an example:-
Poly2_b 5, fil_pat, fil_pen, bg_pen,
0,0,1,
A,0,1,
A,B,1,
0,B,1,
0,0,1
where fil_pat, fil_pen and bg_pen are fairly self explanatory.
I have had a thought since publishing this, and this is that it could be graphic card related, as similar issues happened on earlier releases of AC with certain cards, although this is common to every machine I am using and was not a problem with 7.0.
Cards being used -
NVIDIA Geforce FX5200
Matrox Millenium flex 3D
ATI mobility radion (laptop)
AC 17
Windows 7 Pro
Intel i7-2600
16GB RAM