NX seires controller quirks

I discovered a problem and a solution when using nested waits and IR pulses in the NX series controllers. This popped up when I made a Uverse "favorites" function. I would pulse, wait{, pulse, wait{, pulse, wait{, pulse}}} like I have been doing for many years but it wasn't working consistently. Watching the IR light on the master didn't help me diagnose the problem because it doesn't blink with the pulses. It just turns on and stays on until after the final pulse. I connected an emitter with a confirmation LED and noticed that the WAITS weren't working right. I would see bursts of 3 pulses then a delay or a delay, burst of 2 codes, long delay... no consistency. JZ, in tech support suggested that I try using the Send_Command "SP" and this finally solved the problem.

DEFINE_CALL 'FAVORITES2'
{
SEND_COMMAND dvIR1,"'SP',(F21)"
WAIT 6
{
SEND_COMMAND dvIR1,"'SP',(F22)"
WAIT 6
{
SEND_COMMAND dvIR1,"'SP',(F23)"
WAIT 6
{
SEND_COMMAND dvIR1,"'SP',(F24)"
}
}
}
}