Well my mame source tree is indeed at f:\mame compil\mamesource as it always has been since I started compiling a year ago. My mingw was initially at i:\mingw but since I've started encountering troubles it has moved several times and is now located at g:\mingw
Once again I must emphasize that it worked perfectly a month ago and the months before. I'm pretty sure it's mingw related and the best way to understand what's happening to me is to decypher those ugly messages that appear when I compile. Except it's Babylonian shit to me...