Posting in the Magento forums has been disabled pending the implementation of a new and improved forum solution which should better serve the community.
For new questions please post at magento.stackexchange.com, the community-run support site for the Magento community. We will be providing updates on the new forum solution soon. For questions or concerns please email email@example.com.
Yes, it is also known problem. Some forum functionality was depend on (disabled) search internal function. Now we are working to optimize existing code and then, after this, search function (and all other site parts used it, of course) will be reimplemented.
I know that such limitations are annoying, but its better then downtime because of spam and DoS attacks