One of our forum's spam protections is that a user's first 10 posts are automatically screened for certain common spam phrases and content. One of the things checked for is one or more links to web pages as that's what most spammers include in their posts. Messages found to contain such things go into a moderation queue and must be approved by a moderator before they are publicly posted.
At the present time, you only have 2 posts, including this one, so your messages are still being screened. Your initial post was approved. The link you posted above to your initial post also caused THIS post to go into the moderation queue as well, and as you can see, it has now been approved for public view.
We've only run into this a few times, but it appears that if you have less than 10 posts under your belt, the spam screening will not permit you to submit an EDIT of a pre-existing message if the edit is caught by this screening. Such edits don't seem to go into the moderation queue for approval but are rejected with the error message you received. If you need to have such a message edited, please click the Report link at the bottom of that message and tell us the change that you need to have somebody on the Staff edit into it for you. As an alternative, I think if you delete the links in the message and make whatever other edits you desire, it probably will allow you to submit the edit, but I'm not aware of anybody trying this and reporting back, so at this point this is speculation on my part.
And one other thing, you can only edit a message in the first 48 hours after submission. See
http://www.tugbbs.com/forums/showthread.php?t=38444
As this is really a question about how the bulletin board works, I'm moving this to the About TUGBBS forum.