Editing posts on these forums is time limited. After you have posted a message in our forums, you have approximately 10 minutes to edit it if needed. There are a couple of reasons for this:
First, we have two interfaces on our servers, HTTP and NNTP. The NNTP protocol doesn’t support message editing and the interfaces are synchronized every 10 minutes. If we allowed further editing on the web side, the posts on the two interfaces would become out of sync.
Even if we didn’t have the http/nntp interface issue, we would still limit message editing as once a message has replies, if the original post is edited, the replies may no longer be relevant or could even be dangerous to anyone reading the thread.
For example if I posted “How do I clean off a Windows XP disk?” and someone responded “FDISK is the best way to go”. Imagine now how that reply would read if I changed my original post to “How do I remove a file from my Windows XP disk?” As you can see, the answer now becomes a dangerous one for someone that doesn’t know any better.
If, after the editing window is past you feel the need to edit a post, the best thing to do is to post a follow up reply with the changes and explanation.