I think since moving servers, I've been unable to use the automatic upgrade plugin feature. I've had to manually ftp upgrade the plugins.
Here's the error I get:
Downloading update from http://downloads.wordpress.org/plugin/sociable.2.9.1.zip
Warning: ftp_pwd() [function.ftp-pwd]: Deleted /public_html/.../wp-content/upgrade/sociable/sociable/images/n4g.gif in /home/.../public_html/.../wp-admin/includes/class-wp-filesystem-ftpext.php on line 188
The "Warning: ftp_pwd() [function.ftp-pwd]:..." will repeat itself until I cancel the attempted plugin update.
I'm guessing this looks like a ftp password issue, but it can't be because in /wp-content/upgrade folder I see the new version of the plugin uploaded.