Here's a test build if you'd like to help test before 0.3.9 is released.
(or if you'd rather get upgrading out of the way now instead of waiting)
Downloads: (binaries only)
http://www.bitcoin.org/download/bitcoin-0.3.9.rc1-win32.zip
(http://www.bitcoin.org/download/bitcoin-0.3.9.rc1-linux.tar.gz)
SHA1 a36ea00cce27b4b083755df73a3d1e5e5729884e bitcoin-0.3.9.rc1-win32.zip
SHA1 bbb333b0ea57302740ad1bb9948520d00f884f9d bitcoin-0.3.9.rc1-linux.tar.gz
Edit:
Linux please test rc2 instead. This adds a -4way switch for tcatm's 4-way SSE2. This will only be for Linux:
http://www.bitcoin.org/download/bitcoin-0.3.9.rc2-linux.tar.gz
SHA1 47d9998f7d15fe81234a5c89a542da9d0664df40 bitcoin-0.3.9.rc2-linux.tar.gz
Please report back your results
http://bitcointalk.org/index.php?topic=820