I have found several problems regarding to MSN Spaces, HTTPS, and ping. It"s not too bad for me, Eugene Mironichev, the author of Post2Blog has just replied me. The problems are going to be fixed very soon. For now, I will help him to find ping problem by tracing the log.
This blog is not a complain to Post2Blog. I just want to share my experience of its improvement and its potential to be the best blog client.