This may be overly obvious, but I\'d try these things in order:
1) Setup z for advanced TCP/IP (that\'s what you do, i believe)
2) check computer network connections with ipconfig to see if it recognizes the z address
- if address not correct, pull the usb cable out and put it back, then try ipconfig again after a minute or so.
3) try connecting to the zaurus sync software; if it doesn\'t work, i\'d try a reinstall, as that solved the issue for me once.
Those suggestions may be things that you\'ve already tried, but they\'ve hung me up before...