I've just hit a hard-to-diagnose problem when converting one of the PalmSource DTS examples to the Palm OS Developer Suite IDE. The symptom was an error message coming from a 68K build that reported "garbage following #ifndef", but it reported this error on line 1 of a header file, when there wasn't a #ifndef until line 25.
The issue was line endings. The Eclipse editor can handle Unix, DOS, and Mac style line endings; the version of the 68K compiler shipped in prc-tools is based on GCC 2.95, and it only handles line-endings in the host OS's preferred format. For Windows, it can handle CRLF (DOS) and LF (Unix) style endings. A quick fix for the problem was using the "Edit/Convert Line Delimiters To/CRLF" command in the Eclipse IDE while my Mac-originated header file was the active window. After saving the converted file, I was then able to compile and get a much better set of error messages.