Apple released Mac OS X 10.7.1 (yes, without having first issued a test build to developers). The release represents Apple's first security and maintenance update for Lion, the hugely popular operating system that was released less than one month ago.

The update in question delivers tweaked Wi-Fi reliability and, according to Apple, resolutions for bugs and other bothersome glitches related to audio.

The update, which is available now via Software Update:

Addresses an issue that may cause the system to become unresponsive when playing a video in Safari
Resolves an issue that may cause system audio to stop working when using HDMI or optical audio out
Improves the reliability of Wi-Fi connections
Resolves an issue that prevents transfer of your data, settings, and compatible applications to a new Mac running OS X Lion

Additionally, Apple also pushed out a version of OS X 10.7.1 tailored specifically to the newest MacBook Air and Mac mini models. This update includes the following fixes:

Resolves an issue where MacBook Air may boot up when MagSafe Adapter is attached
Resolves an issue causing intermittent display flickering on MacBook Air
Resolves an issue that causes the SD card slot in Mac mini to run at reduced speed with SD and SDHC media

Source- modmyi