As a result of yesterday's database migration there was an unintended impact on search functionality. Currently search results are returning a traffic jam error page, and saved searches are also not working. You may also notice issues with publishing posts in the Blog, this is because the post is not able to be indexed in the search database. For now we recommend to save draft posts until this issue is rectified.
The Factory team are looking into this at the moment and we hope to have the issue rectified later today.
UPDATE (12/02/2010, 11:55am): The search functionality has been restored. You should be able to use search and saved search and publish blog posts without encountering any issues.