From what I've seen in another thread (in General Discussion), the forum is still a work-in-progress. They're still adding/fixing things. I noticed the forum was extremely slow, or not loading at all, at first. A mod (Jiburiru) mentioned something about the site being overloaded from the volume of users trying to access the forum. However, it seems to be running smoothly for me now, so it seems that issue has been resolved for the most part. The tab thing comes down to preference, I guess. I personally don't mind it automatically launching a new tab since I usually do that anyway, haha. I say give it time, it could be fixed in the (hopefully) near future, along with other potential issues.