Helix DSP.2 pop when turning off vehicle. Remote is connected properly through DSP.

So, I made a thread here several months ago and just recently (FINALLY!) had time to build my new subwoofer box and do a trial run with most of the components hooked up in my car (but not done by any means).

The DSP.2 seems really awesome so far, but I got one fairly loud high frequency pop from my subwoofer (no speakers connected to the DSP yet) after turning my car off the second or third time I tested everything (but not the fourth). I do have the remote lead connected properly through the DSP (I read the manual), and it seems to work as expected overall but it is pretty obvious that the sub amp (old Kicker ZX750.1) actually stays on after the rest of the system has shut down. Also, the system is hitting harder and cleaner than ever (I've had the same sub and amp for 13 years so I know how it sounded in my last car) and isn't losing power at high volumes, so I think my ground is nice and solid. I get no hiss or alternator whine, but I am using an optical connection to the Helix.

I assumed I just needed to adjust the amp shutoff delay, but... apparently that option isn't available on the non-ACO devices, which REALLY stinks. I'm a little surprised that they couldn't add such a simple thing with a firmware update. Perhaps the amp turn-on circuit is hard wired that way in this model.

Is there anything I can tweak in the DSP PC-Tool to fix this on my DSP.2? It doesn't seem to do it every time, but it's currently only hooked up to my sub. I'm terrified to think what it would do to my component speakers when I hook those up. It was fairly loud, despite being well above the range that a sub plays, and it definitely came from the sub.

As a side note, it's possible it is related to my head unit trying to keep the system alive too long after the car has shut off (it lets me choose how long to keep the head unit on before going into standby), but I don't really think so since that should be simply telling the DSP when to shut everything down.

Thanks for any help you can offer!

EDIT: Strange, after getting my laptop hooked back up to the system and checking the DSP Tool again I see that I do actually have a Turn On\Turn Off delay setting, despite not having an ACO-equipped model. This does not seem to be documented in the DSP PC Tool knowledge-base. As I get other opportunities to experiment with my system I will see if this setting makes any difference. As far as I can tell, the setting actually only refers to the DSP itself turning on or off. It doesn't seem to be related to switching off the signal to the remote (amps) at all.