I had tried addition rather than multiplication, but the min/max values were probably still too out of range. From what I see (and seems to confirm in the Csound Manual about VCO2, waveform 2) is that around the 0 and 1 values there can be glitches. So, staying away from those extremes, things sound fine. For the record, below is the new code, with the error eliminated. Thanks again!
;initial values FLsetVal_i 19148,gih1 ;init Cutoff value FLsetVal_i 0.59055,gih2 ;init Q value FLsetVal_i 2.126,gih3 ;init LFO level FLsetVal_i 5.7353,gih3b ;init LFO rate FLsetVal_i 1.0079,gih3c ;init Detune value FLsetVal_i 2,ihBendRange ;init Pitch Bend value
;amplitude envelope: FLsetVal_i 0.01,gih4 ;init value attack FLsetVal_i 2.5263,gih5 ;init value decay FLsetVal_i 0.70706,gih6 ;init value sustain FLsetVal_i 1.9248,gih7 ;init value release
;filter envelope: FLsetVal_i 0.01,gih8 ;init value attack FLsetVal_i 2.3459,gih9 ;init value decay FLsetVal_i 0.09113,gih10 ;init value sustain FLsetVal_i 1.8947,gih11 ;init value release
;initial volume level FLsetVal_i 0.14567,gih12 ;init value volume
;initial sens level FLsetVal_i 0.12782,gih13 ;init value filtLFOlevel FLsetVal_i 9.9248,gih14 ;init value filtLFOrate FLsetVal_i 0.28,gih15 ;init value PWMLFOlevel FLsetVal_i 0.5,gih16 ;init value PWMLFOrate