I seem to have had an issue with comments on this blog for a long time. @NinjaGameDen first pointed out the issue a while back and it appears to only be an issue with putting in a URL when commenting.
I’m still poking at it when I have time, but I suspect it’s how I’ve set up my OpenID config. When you give WordPress a URL when commenting it seems to be trying to validate your identity using that. However it seems most sites fail when reporting back to my blog.
So, hopefully soon I’ll have it worked out.
Edit: I’ve switched off the OpenID option for comments for now, and it all seems to be working. Let me know if there are any issues. Probably via email (hotpinkmonkeysocks at hotpinkmonkeysocks dot com) if you can’t comment.