The cec-client output is pretty much the same. I have emailed Cello in the hope that there is a firmware update.
For the right button, I get repeats like this (here is prs:10):
DEBUG: [ 33933] CLinuxCECAdapterCommunication::Process - ioctl CEC_RECEIVE - rx_status=01 len=3 addr=01 opcode=44
TRAFFIC: [ 33933] >> 01:44:04
DEBUG: [ 33933] SetCurrentButton right (4) D:0ms cur:17f
DEBUG: [ 33933] key pressed: right (4) current(4) duration(0)
DEBUG: [ 33933] key pressed: right (4, 0)
DEBUG: [ 33933] CheckKeypressTimeout T:51142.040
DEBUG: [ 33933] Key right: idle (duration:0) (4) timeout:500ms (rel:500,rep:0,prs:10,rel:0)
DEBUG: [ 33933] >> TV (0) -> Recorder 1 (1): user control pressed (44)
DEBUG: [ 34264] CLinuxCECAdapterCommunication::Process - ioctl CEC_RECEIVE - rx_status=01 len=2 addr=01 opcode=45
TRAFFIC: [ 34264] >> 01:45
DEBUG: [ 34264] key released: right (4) D:3294ms
DEBUG: [ 34264] >> TV (0) -> Recorder 1 (1): user control release (45)
For the down button, I get just one:
DEBUG: [ 36984] CLinuxCECAdapterCommunication::Process - ioctl CEC_RECEIVE - rx_status=01 len=3 addr=01 opcode=44
TRAFFIC: [ 36984] >> 01:44:02
DEBUG: [ 36984] SetCurrentButton down (2) D:0ms cur:17f
DEBUG: [ 36984] key pressed: down (2) current(ff) duration(0)
DEBUG: [ 36984] Changed key down (2) D:0ms cur:ff
DEBUG: [ 36984] key pressed: down (2, 0)
DEBUG: [ 36984] CheckKeypressTimeout T:51145.091
DEBUG: [ 36984] Key down: idle (duration:0) (2) timeout:500ms (rel:500,rep:0,prs:1,rel:0)
DEBUG: [ 36984] >> TV (0) -> Recorder 1 (1): user control pressed (44)
DEBUG: [ 37225] CLinuxCECAdapterCommunication::Process - ioctl CEC_RECEIVE - rx_status=01 len=2 addr=01 opcode=45
TRAFFIC: [ 37225] >> 01:45
DEBUG: [ 37226] key released: down (2) D:242ms
DEBUG: [ 37226] >> TV (0) -> Recorder 1 (1): user control release (45)