hello... well, I think I already replied to you about that....
.... the SendText() function was in the Msgr object, as you mention it. However, this object is part of the private API of Messenger 4. You were already not supposed to use this API and of course, as it's private, Microsoft had no obligation to continue to support it in Messenger 5.
Sorry about this! I suggest you to check out www.mess.be sometimes, they post updates concerning people working on an API... I can already guess that these people will use the Messenger protocol to do it and I personally don't like it. However, I don't say that it's bad so it could be a very good alternative for you.