Thanks to phatt for posting the file here!
Some questions about your build:
1) Did you use J201s or some other JFET?
2) What is your Supply voltage? Have you tried any other?
3) How did you adjust all the trim pots? Have you tried tweeking the pots slightly, maybe a volt high or low from the "ideal"?
4) The slope resistor (R22) seems high, Can you install a trim pot there?
5) Regarding R32 (location F3), did you use 470 ohm or some other value?
Some questions about your build:
1) Did you use J201s or some other JFET?
2) What is your Supply voltage? Have you tried any other?
3) How did you adjust all the trim pots? Have you tried tweeking the pots slightly, maybe a volt high or low from the "ideal"?
4) The slope resistor (R22) seems high, Can you install a trim pot there?
5) Regarding R32 (location F3), did you use 470 ohm or some other value?