A new version of the Bitcoin-Qt and Bitcoind clients from Bitcoin.org, v0.6.2, includes a number of bug fixes and and performance improvements.
http://bitcoin.org/releases/2012/05/08/v0.6.2.html
http://sourceforge.net/projects/bitcoin/files/Bitcoin/bitcoin-0.6.2
http://bitcointalk.org/index.php?topic=80187.0