What brand & model "projectors" are you referring to? I haven't had that problem with Sharp, Yamaha, Dwin, Viewsonic, or Sanyo. I do have issue with the time it takes after issuing a power on command before one can get a projector to respond to an input command. (see other thread "delay after turn on...why).
Sometimes when I run into a device that requires a longer IR command than a tap, simply issuing that command 2-4 times in a row in the macro takes care of it.