Hello,
I also have hangup problems with my w5100 (and arduino Uno)
I Use it as a client to send "midi over tcp" to a digital mixer (Alen & Heath QU 16)
Everything works finie when i send informations, but sometimes the mixer sends some bytes to the arduino -> if there's a few bytes, it's ok, but when there's too much at the same time, arduino freezes.
Do you think that your solution may help me?
Thank you!
some pictures of my project: Dropbox - File Deleted - Simplify your life