Several people have let me know that comments often fail to post / validate. I'm planning on updating to the latest das Blog in a few weeks, after I do some traveling. Until then, I cannot afford to turn off CAPTCHA and I know that not every comment fails. My suggestion (irritating, I know) is to Ctl-A, Ctl-C your comment, try to post it and if it fails, at least you can just Ctl-V it.