its common policy on a lot of forums, as mainly a spam defence, it is not unknown that spammers will post a normal message, then a week later come and edit the post to a spam post - the editing does not flag up to the admins so the spam remains until spotted and reported.
there is also the post one thing - generate a lot of adverse comments, then change the original leaving people wondering why all those adverse comments syndrome. compose in word and paste in is by far the best option if you are about to post a long post.
i sometimes have problems posting here as we have a limited time on non work related websites at work, this cuts in with a banner page informing how much leisure use you have left which can interrupt and disallow a posting here, usually I have to hit accept, and can go back to get to the text I have entered, but sometimes it doesnt work. Hmm - just did it when i tried to post, but I got back ok