Second Digital Box Won't Change Channels

I was recently forced by my provider to change from analogue to a digital service. I received two basic analogue to digital converters and have them setup on media center (win7). I have IR blasters going from the back of the USB MC dongle to the front of the 2 digital boxes.

Problem:

I can browse channels no problem when not recording anything. As soon as I begin recording a channel and change channels, it switches over to the second digital box/tuner but it won't change the channels. Media center seems to think it's changing but the instructions never make it back to the digital box. It's like it's never activating the second IR blaster. I switched some of the hardware around to no avail, same results either way.

Both digital boxes are identical and both remotes worth with both boxes.

Any ideas? Thanks!

I should specify that the remotes will change the channels on the digital boxes no problem and i tried new IR blasters as well as a new USB dongle.