Failing to use k850i as a BT modem

I've been following the instructions at viewtopic.php?f=36&t=789&st=0&sk=t&sd=a and have hit a problem. I can see the phone by Bluetooth:

Code:

[root@localhost ~]# sdptool records 00:1D:28:84:93:DD

Service Description: Sony Ericsson K850
Service RecHandle: 0x10000
Service Class ID List:
  "PnP Information" (0x1200)

Service Name: Serial Port 1
Service RecHandle: 0x2008002
Service Class ID List:
  "Serial Port" (0x1101)
Protocol Descriptor List:
  "L2CAP" (0x0100)
  "RFCOMM" (0x0003)
    Channel: 2

Service Name: Dial-up Networking
Service RecHandle: 0x2008003
Service Class ID List:
  "Dialup Networking" (0x1103)
  "Generic Networking" (0x1201)
Protocol Descriptor List:
  "L2CAP" (0x0100)
  "RFCOMM" (0x0003)
    Channel: 1
Profile Descriptor List:
  "Dialup Networking" (0x1103)
    Version: 0x0101

Service Name: OBEX SyncML Client
Service RecHandle: 0x2008004
Service Class ID List:
  UUID 128: 00000002-0000-1000-8000-0002ee000002
Protocol Descriptor List:
  "L2CAP" (0x0100)
  "RFCOMM" (0x0003)
    Channel: 10
  "OBEX" (0x0008)

<snip>

So I'm interested in Dial-up Networking which uses channel 1 and I create the following /etc/bluetooth/rfcomm.conf file:

Code:

    #
    # RFCOMM configuration file.
    #

    rfcomm0 {
    # Automatically bind the device at startup
    bind yes;

    # Bluetooth address of the device attached to the Acer
    device 00:1D:28:84:93:DD;

    # RFCOMM channel for the connection - use the channel number
    # for DUN found with the sdptool records command...
    channel 1;

    # Description of the connection
    comment "k850i";
    }

So then I run gnome-ppp with the following settings, taken from the instructions (I'm with Vodafone in the UK on a postpay account):

Username: web
Password: web
Remember Password = ticked
Phone Number: *99#

SETUP:
Modem:
Device: /dev/rfcomm0
Type: Analog Modem
Speed: 115200
Phone line: Tone
Wait for dialtone: unticked

Init 2: ATQ0 V1 E1 SO=0 &C1 &D2
Init 3: AT+CGDCONT=1,"IP","INTERNET"

Code:

[root@localhost ~]# gnome-ppp
WVCONF: /root/.wvdial.conf
GNOME PPP: Connecting...
GNOME PPP: STDERR: --> Ignoring malformed input line: ";Do NOT edit this file by hand!"
GNOME PPP: STDERR: --> WvDial: Internet dialer version 1.60
GNOME PPP: STDERR: --> Cannot get information for serial port.
GNOME PPP: STDERR: --> Initializing modem.
GNOME PPP: STDERR: --> Sending: ATX3
GNOME PPP: STDERR: ATX3
GNOME PPP: STDERR: OK
GNOME PPP: STDERR: --> Sending: ATQ0 V1 E1 SO=0 &C1 &D2
GNOME PPP: STDERR: ATQ0 V1 E1 SO=0 &C1 &D2
GNOME PPP: STDERR: ERROR
GNOME PPP: STDERR: --> Bad init string.
GNOME PPP: STDERR: --> Cannot open /dev/rfcomm0: Input/output error
GNOME PPP: STDERR: --> Cannot get information for serial port.
GNOME PPP: STDERR: --> Initializing modem.
GNOME PPP: STDERR: --> Sending: ATX3
GNOME PPP: STDERR: ATX3
GNOME PPP: STDERR: OK
GNOME PPP: STDERR: --> Sending: ATQ0 V1 E1 SO=0 &C1 &D2
GNOME PPP: STDERR: ATQ0 V1 E1 SO=0 &C1 &D2
GNOME PPP: STDERR: ERROR
GNOME PPP: STDERR: --> Bad init string.
GNOME PPP: Unable to KILL wvdial process!

While this is happening the phone has an icon to indicate it's connected to the laptop so I'm reasonably happy that the two are talking.

Can anybody suggest what I can do now in terms of diagnosis or of somewhere else to seek help?

Thanks,
Geoff