Apple released Mac OS X 10.5.8 Update yesterday. The new Mac OS X update includes general operating system fixes that enhance the stability, compatibility and security of your Mac.
The OS X 10.5.8 affects AirPort, Bluetooth, Mac OS X 10.5, Safari 4 (Mac OS X 10.5), iCal 3.x, MobileMe iDisk, Mac OS X 10.5.8 , Mac OS X v10.5.1, v10.5.2, v10.5.3, v10.5.4, v10.5.5, v10.5.6, and v10.5.7.
OS X 10.5.8 also upgrades Safari to version 4.0.2., Improves overall Bluetooth reliability with external devices, Improves the accuracy of full history search in Safari 4 and several more.
Via this Apple support page. Apple released the OS X 10.5.7 in May.