I try (just experimenting) to switch publishing from blogspot to a separate ftp server and i successfully publish my enitre blog to another external host (domain), but since the domain is not mine and set it back to blogspot but when I'm trying to publish again my blog back to blogspot, it gives me "Failed to connect" error.
What I learned was you have to logout first then login again, and check if you choose blogspot.com in publishing your blog and then publish it. Then it works. Sometimes it takes so many clicks and tweaks before we discover how to do things. Anyway at least i have my lesson for the day.