Automatic Plugin Upgrade now asks for connection info?

I’ve been using the automatic upgrade function for my plugins for quite a while. Now all of a sudden WordPress is asking me for “Connection Information” and I’m not clear what I need to be entering. I tried one combination got an error message that my password was incorrect.

So I’m confused and the page is not very explicit (see below). What is the hostname, does it want my WordPress password, or my server password?

And more importantly, why did this crop up all of a sudden?
Here’s a copy and paste from the page requesting the info:

To perform the requested action, connection information is required.
Hostname
Username
Password
Authentication Keys
Public Key:
Private Key:

Enter the location on the server where the keys are located. If a passphrase is needed, enter that in the password field above.
Connection Type
Connection Type FTP
FTPS (SSL)

Any clues would be helpful because upgrading the “old fashioned” way is a real pain – I don’t know which files I should be overwriting when I’ve already customized settings in a plugin. The specific one I’m trying to update is HeadSpace2.

THANKS!