On http://stackexchange.com/filters, I have my favorite tags filter. I setup email notifications for it and now I'm thinking I overdid it on the frequency.
This seems like unfinished planned feature.
Update: Using Chrome Version 29.0.1547.66 m Same on Firefox 23.0.1
Both edit links are not working.
Further Update Events capture:
Update 2014-02-03: Here's what the subscription tab in the network profile looks like.