I recently ran into trouble with K2 v2 stable when I noticed that the "email this article" functionality was including local URLs in the email link instead of gobal. A quick patch to the item.php model corrected this.
I recently started using the latest stable release of the K2 Content Creation Kit component and I think it's awesome, but for some reason they didn't release a plugin for sh404sef with the stable release even though the beta had one.
Recently, while working on a site for my good friend Aaron Axelrod, I needed to make some code changes to the Actionscript in SimpleViewer Pro.