// this works fine:

Contract c;
c.symbol = "IBM";
c.secType = "OPT";
c.exchange = "SMART";
c.currency = "USD";
m_pClient->reqContractDetails((*iter).first, c);

// this gives "Error id=1, errorCode=200, msg=No security definition has been found for the request"

Contract c;
c.symbol = "EOG";
c.secType = "OPT";
c.exchange = "SMART";
c.currency = "USD";