R help - Feb 2012 - non-finite finite-difference value

Dear all,

when applying the optim function the following error occured
"non-finite finite-difference value"

Therefore I would like to ask how one can try to handle such a problem and which
strategies have proven useful. (There is only litte guidance on the help list
for this kind of problem.)

Thank you in advance for your efforts!

Best,

Martin
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