Bleeps on key change with trial Hoster light

[busy bee]

Hi all.I just bought a new lappy and downloaded Hoster Light trial to see if it was compatable with it.It's a Dell Inspiron 1300. 1.5 celeron. 512 memory.40gig hdd.xp home.The manual did'nt give much info on dual display screens but after a bit of digging around on the net I found a way of getting a decent 2 screen solution, The trouble is that when I tried the Key change on hoster as soon as I went up or down,even a semitone each way I got intermittent bleeps of varying pitches.Is this only on the demo version or is it a fault with my equipment.The full version of Hoster Light has worked perfectly on my other lappy without any problems for 5 months now,going on for 80 gigs with it,but I would like to put another Hoster light on this new Dell and use it for backup. Regards to all.B.B