Thank you for your question. I would say I would agree with you regarding the errors you are seeing. Most of the time, it is either a bad cable or a duplex mismatch. However, since you have confirmed that the device connected to switchport 0/13 is also set to auto-negotiate, it would seem to rule a duplex mismatch out. One thing you may want to check is if the NetVanta 1238 and the device connected to switchport 0/13 are negotiating to the same speed and duplex. In this case, you would need to confirm if the device is negotiating to full-duplex with a speed of 100 Mbps.
Another troubleshooting step, you could try is to move the device to another port on the NetVanta 1238 and see whether the issue follows. However, I do not see anything in your switchport configuration that could be causing the errors you are seeing.
Below is a brief description of the ethernet interface errors you are seeing:
Input Errors - The number of data frames that were discarded on reception due to an error being detected in the data frame. This can include runts, giants, crc, and alignment errors.
CRC Errors - The cyclic redundancy check (CRC) value did not match up with the data that was received and can indicate that one or more bits were received incorrectly. This can be caused by a noisy cable or a faulty connection.
Alignment Errors - Caused by misaligned read and writes. For example, the AOS device could attempt a two byte read, but the memory address is not even a multiple of two. This could stem from the CRC errors where it appears that bits are being received incorrectly.
Please do not hesitate to reply to this post if you have any further questions.