I've tried to connect to my MT powered website with w.bloggar but connection failed. I thought that w.bloggar is not doing it's job properly, but saw I'm wrong when I connected to Blogger site (using w.bloggar of course).
Then I tried an app called Drivel, in Linux, but got the same unsuccessful result. I also tried connecting Drivel to the Blogger site and I succeeded. Then, in order to check if something wrong just with my site, I tried another MT powered website and got the same failure.

It says:

Server error
Invalid login

Do you know for this MT's bug/odd behaviour?

Is there a cure for it?

SOLVED. IT WAS THE API PASSWORD STUFF.