And as of this writing, the latest stable CU cannot be April 2012 http://blogs.technet.com/b/steve_chen/archive/2012/04/25/3494397.aspx
+++++++++ Urgent Update !! +++++++++++
There are regressions discovered in the April 2012 CU! Currently the hotfix is in recall from all download servers,
So if you have downloaded but not installed yet, please do not use this CU until next updated version is available!
In case you have already installed the CU and you observe heavy issues or inaccessible lists, Webs and/Or Site Collections, please call MS Support for assistance!
Additional information will be provided as it becomes available.
This only impacts SharePoint 2010!
+++++++++ End of Update +++++++++++