I found I could not use DHCP properly on at least early firmware versions (it would sometimes gather DHCP information OK, but it would generally corrupt later). Fixed IP has always worked fine. I also have 128-bit WEP working.

Try changing it to fixed settings. Be sure to enter the IP, subnet, gateway (your router) and DNS server (likely your ISP), then reboot the unit. If you can get it working at least once, upgrade the firmware right away since there have been a lot of network bug fixes.

Be sure to also check the AP (either lights on the unit or its admin page) to see if it's receiving or transmitting anything to the iPronto (don't go by the iPronto's "connected" graphic).