Cuando agrego mi token ERC20 a una billetera, parece que no tengo saldo

Usé wallet.ethereum.org , metamask y myetherwallet.org pero en todas estas plataformas parece que tengo 0 saldo del token, y no 1000.000 como debería ser. ¿Es un problema en mi código (a continuación) o está en otro lugar?

pragma solidity ^ 0.4.11;
import './IERC20.sol';
contract FuncToken is IERC20 {

uint public constant _totalSupply = 1000000;

string public constant symbol = 'FUNC';
string public constant name = 'Func Token';
uint8 public constant decimals = 3;

mapping(address => uint256) balances;
mapping(address => mapping(address => uint256))
allowed;
function Functoken() {
    balances[msg.sender] = _totalSupply;
}
function totalSupply() constant returns (uint256 totalSupply) {
    return _totalSupply;
}
function balanceOf(address _owner) constant returns (uint256 balance) {
    return balances[_owner];
}
function transfer(address _to, uint256 _value) returns (bool success) {
    require(
        balances[msg.sender] >= _value
            && _value > 0
);
    balances[msg.sender] -= _value;
    balances[_to] += _value;
    Transfer(msg.sender, _to, _value);
    return true;
}
function transferFrom(address _from, address _to, uint256 _value) returns 
(bool
success) {
    require(
        allowed[_from][msg.sender] >= _value
            && balances[_from] >= _value
                && _value > 0
);
    balances[_from] -= _value;

    balances[_to] += _value;
    allowed[_from][msg.sender] -= _value;
    Transfer(_from, _to, _value);
    return true;
}
function approve(address _spender, uint256 _value) returns (bool success) {
    allowed[msg.sender][_spender] = _value;
    Approval(msg.sender, _spender, _value);
    return true;
}
function allowance(address _owner, address _spender) constant returns (uint256
remaining) { 
    return allowed[_owner][_spender];
}

event Transfer(address indexed _from, address indexed _to, uint256 _value);
event Approval(address indexed _owner, address indexed _spender, uint256
_value);
}