You don't need to be reading your transmitter while the receiver is executing a function because of a trigger.
I don't have a delay for my LED marker setup because I have it as a toggle. You can try this bit just to confirm whether the setup is working and not just an improper use of LED handling:
if (vw_get_message(buf, &buflen))
{
boolean static state = false;
if (buf[0] == 'X') {
digitalWrite(ledPin, state);
state = !state;
}
}
change ledPin to whatever you named yours, obv.