Note: the fact that a 'blink' IR emitter was working on the output of the base station (it blinked when a command was sent), means everything is working correctly on the URC system (including routing/preambles).

So now we need to turn our attention to what it is you are trying to control.
1) Can I assume that when you use the URC remote in stand alone (IR being sent straight from remote without base station), that the devices you want to control work?
2) How many emitters do you have and where did they come from (brand)? Have you tried them all? What about the IR blaster that is built into the RF base station?
3) What are the devices you are trying to control?