I am using the latest version of the plugin 0.6.7 (I know, 2008, but author seems to be gone for good) and with my WP version 3.1.3 I get randomly reports from the unique RSS feed key being invalid from several users including mine.
They are working for some time, then suddenly, they fail for certain users, regardless of their role.
1. Anyone can be affected: Subscribers, admins, editors,...
2. resetting don't work
3. Appears to be indirectly browser dependent (session? Login state?) as it sometimes works in FF7, IE8 and Chrome 17.
I could not figure out a pattern at all.
Are there any other similar Plugins that are at least maintained?