Here is my setup:
1 GHz VIA EPIA system
Debian 2.4
LIRC 0.7.7
UIRT2 with firmware version 1.8
The setup records IR codes fine.  I can verify learned codes with irw.  I can use irsend to transmit but the device (a Sharp TV in this case) does not respond to any codes.  I can see the LEDs pulsing with my camcorder. 
I have tried using someone elses remote file I found in remotes.tar.bz2.  I have tried to use irrecord in the "force raw" mode but I just get a "something went wrong" response.  I did this because I thought perhaps the transmit function required raw codes.
Any help would be greatly appreciated.