I'm pretty sure people can be, if not blocked, at least blacklisted. I saw somebody the other day under a slightly different name, and I'd be willing to bet he started a new account because, formerly, all he did was insult people. He was much more polite in his new incarnation.
I doubt that's happened to you gonwk. You might consider starting a new account as a test, anyway. If that doesn't work, it's probably technical, which is my guess. I've had the comments act funky, sometimes. Maybe, it's browser related. What are you using? I believe GOTD is using standard java in it's page coding, and though some people disagree when I say this, I think you have to keep your java fairly up to date with IE or you'll have problems on the site. If you want to try that, the current version is 6.13. Though, I'm no lover of java, enough pages use it that I'm not sure you can surf smoothly without keeping it fairly up to date. You can download here:
http://www.java.com
WR is, as usual, on top of it. I copy to clipboard just in case there's a glitch. As you may know, if it goes through, you'll get the "comment awaiting moderation" underneath your comment. If it goes through twice, you'll get the "you've already said that" message. If you never get either - or, especially, don't even see your post - it's not going through, and I'd say it's definitely technical.