Thanks for your suggestions. However, when I tried implementing them, I had some peculiar results.
When I changed the specular color to black and re-exported all the Cal3D files, Vizard rendered the avatar as a completely black object:
Then, I tried leaving the specular color white and just adjusting the specular level, upping it to 25. After re-exporting the Cal3D files, I ended up with a slightly shinier avatar, but the black spots still appeared in Vizard:
I also noticed a file named *_spec.tga which seemed to be a specular bitmap. Unfortunately, when I tried mapping this to the avatar's specular highlights, I still ended up with spots appearing around the edges:
I notice that the black spots are much more pronounced when the avatar is near the edge of my viewpoint. It seems, also, that the dark spots don't look any different regardless of specular settings (they look exactly the same even when I map the body texture to the specular highlights). Could this issue actually be due to Vizard's rendering? And if so, is there a way I can disable the shadow feature?