Andy, the fact that you got snake-bit by the editor has affected me more deeply than your guidance and directions. Finally, something I _share_ with you. ;^)
Nebur, I've done the 2.7 install from .iso to usb stick. (yes, yes, I know, but am I right that the numbers indicate it might actually be performing decently?) Note that I still had to boost the base, --base 25250, because at 25000 ns, the servo side showed some overflows on the left-hand side.
I have to wonder, since I never remembered to try that with the original setup, if setting the base to 30000 might have stabilized things. I know Tommy suggested it, but I was in a stream of suggestions and before I knew it I was being carried downstream on a different tack.