I installed the Advanced Visual Confirmation mod:
I get the image to display in the registration page however there is no text in the image. The only items that are rendered in the captcha image are background objects like grids, lines, and ovals.
The thread about this mod, appears to be closed:
Any hints or suggestions on how to debug this? My log files are hard to find due to my ISP running virtual servers. Hence, I tried finding some program error messages in apache log files.