This adds a lot of unwanted tags to the text making the post ugly to look at and unreadable. Here is a recent example:
http://www.indiblogger.in/forum/topic.php?id=1196
Also, as a practice, don't cut paste your entire blog post on the forum. The forum is not meant for this.
Just mention the gist or rationale of the post and give the link to your post (if that is allowed, but I see many people doing it) and if people are interested they will look up you post and comment on the forum or directly on your blog.
The general reaction when one sees a huge mass of text on the forum is just to ignore it. So pasting entire blog posts hardly serves your purpose of attracting attention to your post.