ZTE AC8700 USB Modem doesnt work

Binary package hint: network-manager

I have a ZTE AC800 modem that works fine with Ubuntu 9.04. But it stopped working since Ubuntu 9.10. Currently I have installed Kubuntu 10.04 Beta 1. Even now this modem doesn't work through the network-manager. The error I see in the /var/log/daemon.log file is:

Apr 6 09:53:18 skubuntu modem-manager: (ttyUSB0) opening serial device...
Apr 6 09:53:18 skubuntu modem-manager: Modem /org/freedesktop/ModemManager/Modems/1: state changed (disabled -> enabling)
Apr 6 09:53:18 skubuntu modem-manager: Got failure code 100: Unknown error
Apr 6 09:53:18 skubuntu modem-manager: Your CDMA modem does not support +CMEE command
Apr 6 09:53:18 skubuntu modem-manager: Modem /org/freedesktop/ModemManager/Modems/1: state changed (enabling -> enabled)

But this modem still works with wvdial. The settings in the wvdial.conf for the modem are as follows:

Init1 = ATZ
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
Modem Type = Analog Modem
ISDN = 0
Phone = #777
Modem = /dev/ttyUSB0
Username = cdma
Password = cdma
Baud = 460800
Stupid Mode = 1

The way I made it work in Ubuntu/Kubuntu 9.10 was removing the networkmanager of 9.10 and installing the one from 9.04. But thats not the way one would want it to work. Right?

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: konqueror 4:4.4.2-0ubuntu1
ProcVersionSignature: Ubuntu 2.6.32-17.26-generic 2.6.32.10+drm33.1
Uname: Linux 2.6.32-17-generic i686
Architecture: i386
Date: Tue Apr 6 10:24:26 2010
InstallationMedia: Kubuntu 9.10 "Karmic Koala" - Release i386 (20091028.5)
ProcEnviron:
 LANGUAGE=
 PATH=(custom, no user)
 LANG=en_IN
 SHELL=/bin/bash
SourcePackage: kdebase