User's solution

// You need to clean up ALL result sets if you use stored procedures.

// Clean up multiple result sets
while (dbresult)
{
mysql_free_result(dbresult);
printf("mysql_free_result (%s)\n", mysql_error(&dbhandle));
dbresult = 0;

if (mysql_more_results(&dbhandle) && mysql_next_result(&dbhandle))
dbresult = mysql_use_result(&dbhandle);
}