U-235 Suboctave Generator

[mic]

Just built the U-235 Suboctave Generator and find that although it seems generate the lower octaves OK, when a note is sustained even for a short time, the gating tends to be erratic. Adjusting the Sensivity pot' moderatley shifts the trigger point but doesn't fix the problem. Just wondering if anyone has had a similar result. Or if anyone knows a fix.
Thamks, mic