I've written a MIDlet that downloads an image to the phone by using an address. It works prefectly on the emulator but on the phone it won't use the DataInputStream. I've checked the phones MIDP and CLDC version and if any optional packages where being used but all is fine. I've tried it on 3 different phones and none work but it works on all emulators. Could it just be the connection? I left the MIDlet running on the phone for at least 10 minutes and nothing happens.
Did your phones subscribe to data service? Did the phone prompt you to approve the network connection before it tries to connect the web server? Check your server log file to see if there is any incoming connection -- the incoming IP should be mapped to a sub-domain name owned by your' wireless carrier.