@bena, the sequence of numbers are: the first four are ENC28J60 registers EIR, ESTAT, ECCON1 and ERXFCON (all in hex format); followed by a count that detects main loop timeout, and the last one is the available RAM (in KB).
Most of the numbers you have are the same with mine, but one is different after you said it becomes unresponsive: 13 (ESTAT). According to ENC28J60 datasheet, 0x13 means the following bits are set/flaged: Late collision, and Transmit abort. This probably explained why it’s not transmitting data out. Late collision is defined as collision that occurred after 64 bytes have been transmitted. I have never seen this flagged ever on my test controllers. I did some googling and found a few pieces of information here and there:
http://www.firewall.cx/networking-topics/ethernet/195-late-ethernet-collisions.html
I don’t know how to reproduce this situation since I’ve never seen it on my network.