An update to the SDK is available. It can be downloaded here:
http://cycling74.com/download/MaxSDK-5.1.1.zip

Here is the Change Log:
– integrated content and examples from the Jitter SDK
– new jit.simple and jit.simple~ example projects
– all examples are more friendly to XCode versions < 3 for compiling on OS 10.4
– documented CLASS_METHOD_ATTR_PARSE
– fix for example in documentation of CLASS_STICKY_METHOD
– object_zero() deprecated, now does nothing
– class_alias() is now exported from the kernel
– removing the jgraphics lockpixels methods from the documentation — they are not exported.
– fix for definition of JGRAPHICS_3PIOVER2
– commented jgraphics.h regarding jgraphics_pattern_set_extend()
– collect example now includes further information (and an example project) for people wishing to use the Code::Blocks IDE on Windows.
– collect example now includes instructions and Makefile for compiling on Windows using GCC and debugging using GDB.
– collect example now shows how to selectively export symbols for both the Mac and Windows (without using a .def file)