Here is example code that creates a problem: (Goto points have been eliminated for clarity)

F(A1)=FEAT/CYLNDR,INNER,CART,0,0,0,1,0,0,2,-0.625
MEAS/CYLNDR,F(A1),6
ENDMES

F(A2)=FEAT/CYLNDR,INNER,CART,-19.52,0,0,1,0,0,2,-0.625
RMEAS/CYLNDR,F(A2),6,VECBLD,0.25,3
ENDMES

F(A3)=FEAT/CYLNDR,INNER,CART,-32.11,0,0,-1,0,0,2,-0.625
RMEAS/CYLNDR,F(A3),6,VECBLD,0.25,3
ENDMES

F(A4)=FEAT/CYLNDR,INNER,CART,-51.5,0,0,-1,0,0,2,-0.625
RMEAS/CYLNDR,F(A4),6,VECBLD,0.25,3
ENDMES

FA(-A-)=FEAT/CYLNDR,INNER,CART,0,0,0,1,0,0,2,-51.5
CONST/CYLNDR,F(-A-),BF,FA(A1)[1,6],FA(A2)[1,6],FA(A3)[1,6],FA(A4)[1,6]

Of course, this is just one example. Two cylinders will do the same thing. The problem is intermittent.

Bill