1.4.0.3 Cart Issue: No Cart Button, Error when click Checkout button if empty, after order no empty cart sometimes

[Mav]

Who can help me clean up these issues on Blockcart module?

1. If cart is empty and you click the checkout in cart block or cart button on top, a line shows up telling us the parameter is missing but then all other modules stop loading up.

2. Where's Cart button on the shopping cart module?

3. After checkout, sometimes the cart has not been emptied.

Thanks in advance.