Following closely after the release of Safari 5.1.4, Apple today released version 5.1.5 of its Web browser to address difficulties a number of users have had opening the program in 32-bit mode.
Apple's latest hardware and software support has been for 64-bit code, but in order to support older plug-ins and for other compatibility reasons Apple includes a 32-bit binary for its Safari Web browser. To load the software in 32-bit mode, you just need to get information on the application in the Finder and check the "Open in 32-bit" box.
Apparently a significant number of Web sites would not run properly when people ran the 32-bit version of Safari, and this update addresses this problem. In addition, the update includes a couple of stability fixes for people running OS X 10.6.8 and Windows.
It should be available via Software Update, but can also be downloaded from the Safari Web site, if needed. The update will be between 36MB and 48MB, depending on the platform being used, and requires either OS X 10.6.8 or OS X 10.7.3 or later to install. The Windows version requires Windows XP SP2 or later to install.
As always, be sure to back up your system before applying this update.