Cannot post via MarsEdit, displays code on page

We recently upgraded to MarsEdit 3.3.3. We made one successful post with it on the sixth. Today we have had multiple attempts at posting with a return that looks like this:

img style=”display:block; margin-left:auto; margin-right:auto;” src=”http://www.amandasummerlin.com/blog/wp-content/uploads/2011/09/engagement-session-kiss2.jpg” alt=”Engagement session kiss” border=”0″ width=”900″ height=”599″ /

We thought this was an upgrade problem, but when we returned to the previous version of MarsEdit that we have been using successfully for two years, we got the same result. We looked on the MarsEdit support page and found these two urls that appeared to be the same problem; http://www.red-sweater.com/forums/discussion/comment/9923/#Comment_9923 http://josephscott.org/archives/2009/03/conclusion-of-libxml2-issues-use-php-529-libxml2-273/

Spent some time talking with our server, and they don’t support PHP 5.2.9, so we tried the workaround plug-in. It didn’t help.

I am not certain that we are having that exact problem, since it is now being replicated in our previously successful version of the software.

Anyone have any ideas?

(You can view the post at http://www.amandasummerlin.com/blog/ The successful post “Test #5” was made using the WordPress dashboard. I don’t know why MarsEdit would stop working all of a sudden)

Thanks!