I'm using this on an ubuntu box (XBMC Live in fact).  The receiver works flawlessly, but irsend will not transmit.  irsend is aware of the device and can list its codes:

$ irsend list pioneer_vsx_07tx ""

irsend: 00000000a55a50af VOL+
irsend: 00000000a55ad02f VOL-
irsend: 00000000a55a38c7 PWR
irsend: 00000000a55a32cd CD
irsend: 00000000a55af00f VCR1
irsend: 00000000a55a708f VCR2
irsend: 00000000a55ab04f VDP
irsend: 00000000a55a30cf TV
irsend: 00000000a55a2ad5 VSEL
irsend: 00000000a55a728d TAPE1
irsend: 00000000a55ab847 TAPE2
irsend: 00000000a55ae21d TUNER
irsend: 00000000a55ab24d PHONO
irsend: 00000000a55a48b7 MUTE
irsend: 0000000025da807f 1
irsend: 0000000025da40bf 2
irsend: 0000000025dac03f 3
irsend: 0000000025da20df 4
irsend: 0000000025daa05f 5
irsend: 0000000025da604f 6
irsend: 0000000025dae01f 7
irsend: 0000000025da10ef 8
irsend: 0000000025da906f 9
irsend: 0000000025da00ff 0
irsend: 0000000025da6a95 FREQ+
irsend: 0000000025daea15 FREQ-
irsend: 0000000025dac837 BAND
irsend: 00000000a55a58a7 POWER_ON
irsend: 00000000a55ad827 POWER_OFF

but if i run any irsend command to transmit, the talkback LED doesn't flash (i have confirmed the talkback does work with another device) and nothing is sent.  i've even tried setting the transmitter

irsend --device=/dev/lircd SEND_ONCE $REMOTE_NAME POWER_OFF

i've tried SET_TRANSMITTERS 1 and SET_TRANSMITTERS 2 independently as well.

as a test, i created a .lircrc and ran irexec to view the output:

$ cat .lircrc
    remote = pioneer_vsx_07tx
    button = MUTE
    prog   = irexec
    repeat = 0
    config = echo "Hello world!"

here's the irexec output:

$ irexec
Hello world!
Hello world!
Hello world!
Hello world!

activity in the daemon log confirm that the daemon is seeing the "client" connection:

Jun 18 02:10:21 XBMC-lr lircd-0.8.4a[1675]: accepted new client on /dev/lircd
Jun 18 02:10:21 XBMC-lr lircd-0.8.4a[1675]: removed client
Jun 18 02:12:50 XBMC-lr lircd-0.8.4a[1675]: accepted new client on /dev/lircd
Jun 18 02:12:50 XBMC-lr lircd-0.8.4a[1675]: removed client
Jun 18 02:12:50 XBMC-lr lircd-0.8.4a[1675]: accepted new client on /dev/lircd

here is the lsusb output:

Bus 001 Device 003: ID 13fe:3100 Kingston Technology Company Inc.
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 002: ID 1784:0008 TopSeed Technology Corp.
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub

and here is the output of dmesg | grep lirc:

[   16.935417] lirc_dev: IR Remote Control driver registered, major 61
[   17.325098] lirc_mceusb2: Philips eHome USB IR Transceiver and Microsoft MCE 2005 Remote Control driver for LIRC $Revision: 1.51 $
[   17.325100] lirc_mceusb2: Daniel Melander <lirc@rajidae.se>, Martin Blatter <martin_a_blatter@yahoo.com>
[   17.739160] lirc_dev: lirc_register_plugin: sample_rate: 0
[   17.745158] lirc_mceusb2[2]: Topseed Technology Corp. eHome Infrared Transceiver on usb2:2
[   17.745186] usbcore: registered new interface driver lirc_mceusb2