Problems with tether to WM6 device

I've got a Bold, v.282. With Rogers, and a Tethering plan.
I can connect to PC (XP, SP3) via BT & establish Internet connection & browse pages.

When I follow the same procedure (BT partnership, dial-up number...)
with a hand-held device running Windows Mobile 6, indicates an Internet connection, and BB is in 'modem mode enabled', but no web pages load.

I can't explain why it's working successfully with laptop XP operating system but not WM platform.
(my colleagues' Bold, (he's had it for more than a year) same data plan & configuration with WM6, works successfully with WM platform & laptop.)

Any ideas/suggestions are greatly appreciated.

Heather