I'm new to WordPress so I'm not sure if this is 100% WordPress or K2 (I'm using the K2 theme currently), but if it's K2 then just let me know and I'll let them know.
Basically...when you enter text for a tag and press enter, it adds the tag, but if the tag has been used in the past then the drop down menu lists the tag again after pressing enter. I clicked on the tag that I entered and it updated the textbox with the new tag, but the color was gray.
If you need more explaination just let me know. It's a small bug, but details matter. I'll look at the script later and see if I can figure out where it's going wrong, but until then, you guys have fun!
Thanks for such an awesome blogging setup! I now love WordPress and the community!