Finally, Michael_Gombkoto´s solution in the Xbox Remote Thread did work just fine. I created a new lircmap, and everything seems to be fine, button presses are quite instant and nomore double-presses needed.
Strange, as the new licd is exactly the same as the old one, at least what I read out of the file.
Thx, fzinken!
edit:
still issues with xbox remote, see this thread: