When I boot my system, I usually need to boot twice!

in the first time, my system works but my monitor does not work! also, i can hear a "BiB!" sound after my system boots while my monitor is still dead.

in the second time, after I need to turn off my system and monitor power, my system and monitor are working. Do you have this problems? please tell what you think?

i head about i need to warm up my monitor, is it right? how come??

thanks