Captcha issue(s)

Consider this a bug report on that wiki though -- the captchas are broken: [1] sometimes characters are drawn beyond the image's edge (I just saw half on "o"; could just as well have been a "u" for instance), and [2] some characters are drawn indecipherable; characters like "O", "o", "Q" or "I" and "l", should be excluded from beying used in captchas because it's impossible to see the difference.
For this one simple edit I needed to go through four unnecessary captchas due to this. Such barriers don't motivate users to contribute.