sync pocket pc with win xp

Recently, I purchased Dell 4550 desktop (with windows XP) and Dell AXIM pocket PC. Both systems work well, but I was never able to synchronize them using Microsoft’s ActiveSync 3.5 or 3.6 with either a USB cradle or a separate USB wire. (Microsoft Outlook)

I spent 5 hours on the phone with the Dell's Desktop Support, Pocket PC Support, and Software Support. Nobody was able to help me.

What I found myself is following:
1. The USB ports of my Dell 4550 are working well as they can be used for other devices;
2. My AXIM works well and can be synchronized with my laptop which runs under Windows 98, using Microsoft’s ActiveSync and USB cradle or USB cable.

Interestingly, my son had similar problems with synchronization of his Palm OS-based device with his desktop, using USB port connection (windows XP). He finally was able to achieve synchronization, using a serial port cradle. Unfortunately the Axim does not yet have a serial cradle

On the Internet, there are two groups of people discussing synchronization issues related to Windows XP: one group reports that they have had no problems and another group reports that they were never able to synchronize their pocket devices with their desktops using USB connection.

Can you please help me work this problem out?