Node.js on windows: express.js app.get routing with files doesn't work

nodejs 0.8 on Windows with express:

Custom routing:

app.get("/less/file.less",  function(req, res){
  res.send("XXX");
});

If a file is available via URL (for example /less/file.less - public) it propose to download file, instead of returning "XXX" response. I have other behaviour on linux machine.

What can be is wrong? Is it possible to fix?

A