I have had users complaining about this and was able to recreate it myself just now when trying to login with Facebook. I think the users who have had this happen (also while trying to login) where doing a normal non-Facebook login.
I sure wish that I could..... Several other users reported it as well. All seemed to be on the login page. Perhaps if you could explain why it is unavoidable, I would have a better idea what to look for.
Hi Mike -- I know this is a couple of weeks old, and I don't know if you've gotten any more details about it, but I had a similar experience using silence's external accounts extended, when you try to use it from the from the /login/login page (ie, after a user makes an error trying to log in initially) --
The context there is -- if it's specific to his login types -- that it'd be a bug in the add-on code to some degree. It is difficult to prevent entirely though because it's just redirecting back to the page the users were on.