Adding Category Failed To Appear Instantly and Oops error Message On Header For Wordpress 3.0.5 and

I'm not sure this is multidb related question or not, because it may be that multidb is the cause of the error. Anyway, I have upgraded wordpress 3.0.4 to 3.0.5, and then the problems apparently sprung into existence. What are the problems?

Create a blog as a member, login to dashboard, and add a new post. At the new post editor page, I try to add a new category, but the category isn't appearing to be working, but only refresh the page shows the category has been added. This means something about javascript or jquery or whatever that makes adding category to look instantly add on this very page isn't working. Click on preview link will also not work unless a member have saved the post as draft or publish the post and then click on preview change link then it will work. The oops message appears on top of the header right below the buddypress admin bar. Also, adding category may also generate an oops categoryname]]> message/error.

View a screenshot of this problem at here.

Is this a multidb error or a bug inside wordpress 3.0.5? I'm using multidb 3.0.5. Using php5+ and mysql 5+ and apache 2+. Installing latest buddypress and wordpress 3.0.5 and everything else on dedicated server and so there is no restriction on server settings.