Thanks! I also have this problem - 2008 Lexus IS 220D bought in Seyssin, France (near Grenoble). So as I understand it, your fix is to unplug the battery for 10 minutes to force the ECU to relearn. Is that right?
I'm wondering if that might not fix another nagging problem that nobody at Lexus can solve: I can't unlock all car doors from the driver's side door, nor with the key. I've always suspected this was some sort of software problem. Could this be some system that needs to relearn?