The reason I bought the SX-66 was its WPA support. I had another PDA, but it only supported WEP and was not upgradeable to Windows Mobile 2003. SO I got the SX-66 (from Cingular).
My Netgear Wireless router supports WPA, and both my laptop and wireless USB card connect using WPA-PSK with no problems. But my SX-66 can only connect if the router is set for no encryption or WEP, but NOT WPA. I have tried every update and support site for Windows, Windows Mobile (except 5.0, which is not available for the SX-66), Netgear, Siemens and Cingular. Each vendor politely tells me it's some other vendor's problem.
I have heard from some colleagues that their WM 2003 PDAs have similar problems with WPA-PSK, but I have also heard and read of others who connect their PDAs via WPA with no problems.
I would give/pay a great deal (aside from buying yet ANOTHER PDA) if I could get my SX-66 to be able to connect to my router using WPA encryption, as it is supposed to be able to do.