The reply I got this morning indicates that the site is still being worked on:
"Thank you for contacting FamilySearch concerning searches in the Ireland Civil registration collection.
The Ireland Civil Registration collection is subject to engineering work throughout May and our engineers may need to take the collection down and reload it as they work on a series of new versions of the search engine. We believe you refer to one of these periods of essential engineering which take place on weekdays.
We have restored a place filter for search by county and hope that this work does not disrupt your research in future.
The search engine may not be stable during the engineering work period explained above. Please let us know of any difficulties which will be considered by the team responsible for the search engine.
We would be happy to replicate your search for an individual if you are experiencing difficulty in locating a result if you can give us details of the name, type of event date and place. It is difficult for us to respond to general comments about data within the index as we need to ensure that the individual names search is working.
The essential engineering is taking place to transfer the index to a new search engine which is now available for public beta test. If you would like to view historic record collections and offer feedback please go to
http://fsbeta.familysearch.org/ Please reply with your unique case number 16xxxx and Record Search in the heading and we will be pleased to assist you further. You may offer feedback using the Family Search beta site feedback system on that site.
We hope that you will continue to use Record Search as a research resource. Please check it often as new collections are added to it frequently. May we also tell you about the wiki found at wiki.familysearch.org? It has background information about our collections and also points to many other databases that may have content that may be of interest to you. You may also post questions about the research you are doing on our forums found at forums.familysearch.org. We would encourage you to register for both with a single account id and password. Assistance to do so is available on the sites.
Sincerely,
FamilySearch "
Using the Beta search on the Civil Index shows 40493 results for James Byrne but does not seem as user-friendly as it doesn't show filters.
Dara.