A receive-alignment error means that the card has received a damaged frame from the network. When one of these errors occurs, it also triggers an FCS (Frame Check Sequence) error. These errors occur if the received frame size isn't a multiple of eight bits (one byte).
These errors are commonly due to faulty wiring, cable runs that are out of the IEEE 802.3 specification, a faulty NIC, or possibly a faulty hub or switch. To narrow down this problem, do a binary division of the network to help eliminate the source.