There are many places in the C++ code that mix uint32_t, usually in the form of an encoding or Buffer size, with size_t, usually the result of a size() call to a string or some other container. In a Windows 64-bit build this produces a warning for each occurrence similar to:
3>C:\ace\exported\qpid\trunk\qpid\cpp\src\qpid/broker/Exchange.h(122) : warning C4267: 'return' : conversion from 'size_t' to 'uint32_t', possible loss of data
This type of code is present in both hand-written and generated code, which is why I included the Code generator in the Components.
Some can be removed with a cast - for example, the Uuid::encodedSize method isn't going to return a value greater than 2^32-1, so it can be safely cast away. But the problem should be dealt with more cleanly, I think.