Hi all
I used to have the same problem in the last couple of weeks when accessing the contribs forum (both at home and at work, during the day and late in the evening). I usually right click on a post and open it in an new window/tab. After I opened about 5 or more posts I hit the same bwshare module. I use IE7.
The last few days I haven't had any problems but maybe that's because I've logged myself "permanently" in on the forum. Before that, I browsed the forum as a guest and only logged in if I wanted to reply to a message.
Maybe you can try to do the same. If the problem persists and other people experience the same problem, you should post it in the bug tracker.
Edit: Aarrgh!!! Just after posting this reply I hit the bwshare module again:
Service Temporarily Unavailable
The bwshare module will refuse your requests for the next 58 seconds.
You have made too many requests per seconds.