This morning I adjusted the NPRO diode temperatures to see if they would affect the behaviour of the FSS and the locking of the
IMC.

initial temperatures as read from the front panel of the NPRO power supply.
D1 : 18.30
D2 : 16.00
final temperatures
D1 : 18.39
D2 : 15.96

    Both the FSS and IMC remained locked whilst I adjusted the temperatures.  To see if there was any difference in behaviour
I unlocked and locked the IMC a number of times, whilst watching the FASTM strip chart in the FSS MEDM screen.  Each time the
IMC acquired lock without the FASTM "mis-behaving".  Then I increased the common gain slider to 30 dB to see if that would
change the behaviour.  The IMC appeared to re-acquire without any problems and FASTM did not exhibit any "mis-behaviour".
I tried to see if the IMC would re-acquire with both the common gain and fast gain set to 30 dB but ran into problems with the
FSS oscillating.  Note that we'd never run the FSS with both gains set that high.

    On the ~15 times I've locked and re-locked the IMC, the FSS seemed to be well behaved with the common gain at 20 dB
and the fast gain at 3 dB (ie, the current operational settings).  The time I did have problems were because of the ISS railing.
Whilst ~15 times is not an exhaustive test, only time will tell if the diode temperature adjustment really helps fix the problem
observed with the IMC locking.

    IMC_Lock.png shows the attempts at locking the IMC.  The two bursts in the top trace correspond to periods of when I tried
it with the common gain set to 30 dB.