http://www.macnn.com/articles/10/10/14/pro.express.updates.available/
Logic 9.1.2 updates fix Mac Pro, AU compatibility
updated 05:30 pm EDT, Thu October 14, 2010
Pro, Express updates available
Apple has posted matching v9.1.2 updates for Logic Pro and Logic Express, the company's professional-grade audio production suites. The patches are oriented strictly at stability and compatibility, most notably in terms of improving support for six- and 12-core Mac Pros. Compatibility has also been improved for some Audio Unit plugins.
REX files are newly supported in 64-bit mode, and each suite can now link with iOS control apps based on the OSC protocol. The Logic Pro download is 193MB; the Express version is 140MB. English, French, German and Japanese translations are available.
