Tvheadend

On my SAT>IP Tuner (Triax TSS400) I have three of the inputs enables

"Astra 28.2ºE α" is connected directly to it's own feed
"Astra 28.2ºE β" and "Astra 28.2ºE γ" are connected via a splitter to a second feed.

"Astra 28.2ºE β" has the "Master Tuner" set to "This Tuner"
"Astra 28.2ºE γ" has the "Master Tuner" set to "Astra 28.2ºE β"

If you tie "Astra 28.2ºE α" up with a recording it tunes in and happily records it.
If you then set a recording going on "Motors TV" (12.515H - i.e. High Band Horizontal) it records as expected on "Astra 28.2ºE β"

If you tune to movies4men +1 which is broadcast on 12.663H (i.e. High Band Horizontal) you get "No Free Tuner" in XBMC and

2014-07-11 20:56:24.043 subscription: No transponder available for subscription "127.0.0.1 [ XBMC Media Center ]" to channel "movies4men +1"

where as I would expect it to use "Astra 28.2ºE γ" for this.

I have tried restarting TVHeadend to no avail.

One thing that may, or may not, be related is that if the third input on the Triax was tuned to a High Band Horizontal transponder (e.g. using the Sat>ip Alignment app) the tuner stayed forever on that frequency which meant that the other tuner fed from the same feed could only see High Band Horizontal transponders. If it was parked on a low band horizontal frequency then all Horizontal channels were available. To get Tuner 2 working on all transponders it needs to be parked on Low Band Vertical - when switching any of the tuners in the pairing I would expect the others to be tuned to a frequency in the same band.