Playing loops in Max 8 with M-Audio Trigger Finger--pops at zero

Hi all. I've been using Max for several years to improvise with pre-selected audio loops, mostly using the knobs on my M-Audio Trigger Finger to control the loop speed, only playing the loops forward, and then having the loops stop when the knob hits zero. I'm so sorry for the ugliness of this patch :) but here's the way one of these loop players looks in Max 5:

Upon switching to Max 7 and then 8, I find that this setup creates an unwanted pop every time I go to "zero" to stop the loop from playing. This never happened in Max 5 with the above setup.

I've had some help from a TA to try and fix this problem, and here are two screen shots of the patch he's created using grooveduck2 and some of his own attempts to figure it out.

And then here's inside the grooveduck2 object which he tweaked a bit:

I'd love to get a simple loop player working that allows me to control loop speed with the knob, that doesn't add the pop when I go back to zero after playing a loop. Any suggestions?