Problem connecting Bluetooth T610 - Notebook: Modem no response?

I've been using Vodafone UK GPRS with my old Ericsson R520 and my
Notebook (Win98SE) with a 3Com Bluetooth PC Card without any problems.
Lately, I upgraded to the T610 but have not been able to get the
connection for modem dialup working at all. What I've done so far:

- I've paired up the T610 and the 3Com BT Card. No problems there -
was able to send a business card from notebook to phone which received
it. So I know the bluetooth connection is fine.
- When I try to use the 3Com Bluetooth DUN Client to connect from
notebook to T610 for both GPRS and normal mobilephone connection, it
fails. I even used the 3Com BT DUN Client to call up my demon ISP tel
number 0845etc and the DUN client on my notebook keeps on saying that
the T610's modem is not responding.

I checked the log and it shows this:

114200,N,8,1
Initializing modem.
Send: AT<cr>
Recv: <no response>
WARNING: Unrecognized response. Retrying...
Send: AT<cr>
Recv: <no response>
WARNING: Unrecognized response. Retrying...
Send: AT<cr>
Recv: <no response>
WARNING: Unrecognized response. Retrying...
Send: AT<cr>
Recv: <no response>
WARNING: Unrecognized response. Retrying...
Send: AT<cr>
Recv: <no response>
ERROR: Unable to recover from unrecognized response.
ERROR: Dial failed.
Hanging up the modem.
Session Statistics:
Reads: 0 bytes
Writes: 30 bytes
3Com Bluetooth DUN Client closed.

My settings for 3Com Bluetooth DUN Client:
Port: COM5
Max Speed: 115200
Connection N81
Port Settings: High both, Use FIFO Buffers
Advanced: Use flow control/Hardware checked. Extra settings: AT
+CGDCONT=1, "ip","internet"

Any idea why my t610 modem is NOT RESPONDING at all to a standard AT
command?

Please, any help greatly appreciated!