Some people (most notably, yours truly) are seeing double notifications and/or doubled items inside of notifications. This only happens for feeds that are in groups. What’s happening is that a walker claims the feed group and starts processing it. At about the same time, a different walker claims one of the feeds inside the group. The first walker, processing the feed group, also process all the feeds inside the group — just to make sure everybody’s got the latest data– and so the same feed ends up getting processed twice at the same time. This is a pretty classic example of what’s called a race condition in the programming world.

Anyway, boring details aside, there should be a fix for this soon.