About the sources to classes: The debugger has to check the project being debugged, and there are a number of possibilities:
– The class is from a source folder, so that source can be shown.
– The class is from a library with sources attached, so that source can be shown.
– The class is from a library with no sources attached, so the byte code needs to be de-compiled into a source file (isn’t that easier with Eclipse 3.3 now?).