This is an issue with caching, as Nope stated. You'll need to find a shortcut for your preferred browser that will reload the cache for the website. For Firefox it would be Ctrl+Shift+R or Command+Shift+R.
This is related to the 'friends bug'.
@ScruffyRules: What's the friends bug?
@ScruffyRules: no, it's just caching issue. Sidebar has no cache buster so it always will show whatever is cached previously. Disabling cache will update sidebar properly.
@Nope: +1 for correct info. tested and confirmed its a local caching issue.
Just had this after the friends fix so yeah, not that.