I understand you need to keep bots off the site...however this particular form of spam protection is very hard on the eyes and difficult (for me anyway) to understand. Had a thought however recently visited a site and rather then this type of captcha they had a picture format.
How that worked was you were presented with a few small pictures (cat, dog, bird) etc and asked to select one based on the hint given ie "please click on picture of the dog", was very easy on the eyes and did not make posting feel like such a painful process?
Anyway love the game and hope to become a regular poster on the forums eventually!