Tud, a lot of people here are frustrated by the commenting system. When you post a comment here it gets swallowed. Always. The only way to prevent it is to copy the text of your post, refresh the page and paste it back in and post it as quickly as you can. It's been reported but no one does anything about it.
[In fact just yesterday, the site administrators applied another patch to try to fix the comment bugs. So it's definitely not the case that no one does anything about it. In fact, it's probably the #1 issue for the site administrators. -Raymond]