I have ubuntu, and I'm trying to chat like I normally do on deviantart, with more than one chat open at once. However, I cannot use tab normally (the tab button makes the cursor vanish rather than helping me type people's usernames), and every time I hit enter, the page refreshes. What am I doing wrong, or how on earth can I fix this? I need to do both of those things without constant refreshing in order to function in the dA chats properly.
Since I do not use DA chat before I just made quick test with multiple tabs and for me Tab and Enter buttons work property.
I notice that chat is based on Flash so believe it could be problem with your browser flash plugin (maybe it not updated, or non-free is required to be used).
My suggestion would be: