I have a Z4000 with the discontinued wireless remote.
Periodically when I have track 2 selected and am repeatedly pressing WHISTLE (e.g. for a PS2 sequence), the whistle on track 1 will activate and get stuck on. The only way to shut it up is to switch tracks and hold the whistle down for about 3 seconds.
Is this an oddity, or is this among the reasons the remote was discontinued?