Beeps when chaging from tripple mode to tv out with Parhelia

[Skee^]

Im runnig my Pc with 3 monitors, when i wanna se a movie on my tv i must shutdown the pc and change monitor output 1 on the splitted cable to my Tv out cable. but when ive done that and starts up yhe pc it starts to beep and no picture so i have to wait a moment. same thing when going back to tripple mode.

what is this...