Over the weekend, Apple began seeding a new test build of Mac OS X 10.6.3, developer sources say. Labeled 10D548, the build is said to be little different than 10D538, with similar emphasis on improving the security, compatibility and reliability of QuickTime X, as well as the performance of the Logic audio editing suite. Tweaks are also said to improve compatibility with printers, and apps based on the OpenGL rendering platform.