Phuah Yee Keat, thank you very much, it worked, although there is a remaining problem discussed below which does not prevent it from working now.

madbiologist, I very respectfully disagree that it is a new bug, it seems to be a regression caused by this bug fix, because it did work correctly some time ago, before this bug first appeared. I never posted a dmesg, lsusb etc, because they were all perfectly normal. But because some more information is now available, I will post them now. Because VMC is now usable I can confirm that the wrong device ID is being reported somehow as a K3520 to VMC, while lsusb correctly shows E620.

The relevant part of the uname -a output is 2.6.32-020632-generic #020632 SMP Thu Dec 3 10:09:58 UTC 2009 x86_64 GNU/Linux

lsusb:

Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 003: ID 12d1:1001 Huawei Technologies Co., Ltd. E620 USB Modem
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 002: ID 046d:c019 Logitech, Inc. Optical Tilt Wheel Mouse
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub


which is correct!

relevant part of dmesg:

[ 3605.392569] usb 4-1: new full speed USB device using ohci_hcd and address 8
[ 3605.622343] usb 4-1: configuration #1 chosen from 1 choice
[ 3605.628244] scsi21 : SCSI emulation for USB Mass Storage devices
[ 3605.628852] usb-storage: device found at 8
[ 3605.628859] usb-storage: waiting for device to settle before scanning
[ 3605.690069] usbcore: deregistering interface driver option
[ 3605.690196] USB Serial deregistering driver GSM modem (1-port)
[ 3605.720850] usbcore: deregistering interface driver usbserial_generic
[ 3605.720995] USB Serial deregistering driver generic
[ 3605.721052] usbcore: deregistering interface driver usbserial
[ 3605.792598] usb 4-1: USB disconnect, address 8
[ 3605.992436] usbcore: registered new interface driver usbserial
[ 3605.993361] USB Serial support registered for generic
[ 3606.252725] usbcore: registered new interface driver usbserial_generic
[ 3606.252736] usbserial: USB Serial Driver core
[ 3606.261873] USB Serial support registered for GSM modem (1-port)
[ 3606.262056] usbcore: registered new interface driver option
[ 3606.262062] option: v0.7.2:USB Driver for GSM modems
[ 3606.590087] usb 4-1: new full speed USB device using ohci_hcd and address 9
[ 3606.821405] usb 4-1: configuration #1 chosen from 1 choice
[ 3606.827675] option 4-1:1.0: GSM modem (1-port) converter detected
[ 3606.827973] usb 4-1: GSM modem (1-port) converter now attached to ttyUSB0
[ 3606.841188] option 4-1:1.1: GSM modem (1-port) converter detected
[ 3606.841454] usb 4-1: GSM modem (1-port) converter now attached to ttyUSB1
[ 3606.857970] option 4-1:1.2: GSM modem (1-port) converter detected
[ 3606.858255] usb 4-1: GSM modem (1-port) converter now attached to ttyUSB2
[ 3606.880895] scsi25 : SCSI emulation for USB Mass Storage devices
[ 3606.890283] usb-storage: device found at 9
[ 3606.890296] usb-storage: waiting for device to settle before scanning
[ 3611.892234] usb-storage: device scan complete
[ 3611.896168] scsi 25:0:0:0: CD-ROM            HUAWEI   Mass Storage     2.31 PQ: 0 ANSI: 2
[ 3611.900139] scsi 25:0:0:1: Direct-Access     HUAWEI   SD Storage       2.31 PQ: 0 ANSI: 2
[ 3611.930097] sr1: scsi-1 drive
[ 3611.935151] sr 25:0:0:0: Attached scsi CD-ROM sr1
[ 3611.938369] sr 25:0:0:0: Attached scsi generic sg3 type 5
[ 3611.943446] sd 25:0:0:1: Attached scsi generic sg4 type 0
[ 3611.978151] sd 25:0:0:1: [sdc] Attached SCSI removable disk


I believe that to also be normal. So why does VMC now report the device as K3520? Before the bug it was correctly shown in the VMC config window as E620.

This does seem to have been a very difficult and tedious bug to fix, and I do appreciate the hard work of those involved, but it seems to me that the fix is almost but not quite complete, yet.

If you need any more diagnostics from me please ask, as I would much rather help to fix it than complain about it.