What is your video card? It looks like a possible corruption of the GPU render.
Yes, triangulation artifacts on non-convex shapes. Simply import the paths differently so the inner text isn't considered as a "hole". Also clean the paths up and remove redundant anchor points.
Thank you very much for your reply.
Could you please explain to me how to import the paths in the manner you describe? I'm not overly familiar with Illustrator, other than loading and saving artwork.
If it's any help, here is the Illustrator file as supplied to me: homepage.ntlworld.com/mike1962/cnet.ai
My card is an Nvidia Quadro FX 3800. I regularly update the s/w to the latest version.