Sorry for the late reply! I was on vacation and then forgot to check...
what voltage are you feeding them? is the psu powerful enough ?
unrelated, but I have a pair that I love but wasn't able to find a proper calibration procedure, and to have them stereo linked ? do you have informations regarding this ?
I have +/- 10V output from the power supply (it's the same with 9V btw). I use LM337 and LM317, so theses should be able to supply more than enough current for the two modules.
I couldn't find any information on calibration of the limiter module (it does have trim pots), the only thing I have done is set the limiting threshold with P4. To link the two modules I just connected the two control voltages on pin 28.
also, did you toy with the time constants? sounds like a very fast attack / bug thingie going on, and if the channels are linked, both the sidechains are working and both unit compressing..
Only the release time is adjustable and it doesn't seem to have an effect on the clicking. I forgot to mention: in the sample I posted, the units were NOT linked! So the only connection between them is through the power supply.
Sounds like the control voltage is leaking into the audio.
I don't know how this would happen....

The next thing I will do is to use another power supply and see if the problem is still existent.