[R] optim error

[Frank Black]

Dear all,

There have been one or two questions posted to the list regarding the optim 
error "non-finite finite-difference value [4]."  The error apparently means 
that the 4th element of the gradient is non-finite.  My question is what 
part(s) of my program should I fiddle with in an attempt to fix it?  
Starting values?  Something in the log-likelihood itself?  Perhaps the data 
(which is generated)?  Any thoughts would be greatly appreciated.

Thanks, Frank