It can seem like no one knows what they are talking about, especially if the responder doesn't know what you have already done to troubleshoot the problem.
If I am redundant, I apologize. If you have iPAQ Wireless Pack for GSM/GPRS Networks, it simply will not work with windows mobile 03. As of 9-09, HP has no fix.
Make sure you have the latest drivers from
HP. Pay particular note to network drivers, but also other updates can have an effect as well. If you have already tried the above, please leave more info on when the problem started and whether wifi shows availability.