Failed to run network connection

[Guest]

After riding last Karmic beta with no problems at all, I tried RC and failed to connect to Internet.
I used to connect via Huawei E220 modem.
Knetworkmanager allowed me to create connection, but not responsed my tryes to establish it.
Kppp failed too. It log-screen stayed blank during connection.
Wvdial provided log:

da3mon@da3mon:~ $ wvdial
--> WvDial: Internet dialer version 1.60
--> Cannot get information for serial port.
--> Initializing modem.
--> Sending: ATZ
ATZ
OK
--> Sending: AT+CGDCONT=1,"IP","internet"
AT+CGDCONT=1,"IP","internet"
OK
--> Modem initialized.
--> Idle Seconds = 300, disabling automatic reconnect.
--> Sending: ATDT*99#
--> Waiting for carrier.
ATDT*99#
CONNECT
--> Carrier detected. Starting PPP immediately.
--> Starting pppd at Sat Oct 24 17:19:08 2009
--> Warning: Could not modify /etc/ppp/pap-secrets: Permission denied
--> --> PAP (Password Authentication Protocol) may be flaky.
--> Warning: Could not modify /etc/ppp/chap-secrets: Permission denied
--> --> CHAP (Challenge Handshake) may be flaky.
--> Pid of pppd: 3243
--> Disconnecting at Sat Oct 24 17:19:08 2009
--> The PPP daemon has died: pppd options error (exit code = 2)
--> man pppd explains pppd error codes in more detail.
--> I guess that's it for now, exiting
--> The PPP daemon has died. (exit code = 2)

This error appeared after my first plug modem om. But if run wvdial the second time without replug the modem, error comes:

--> WvDial: Internet dialer version 1.60
--> Cannot get information for serial port.
--> Initializing modem.
--> Sending: ATZ
--> Sending: ATQ0
--> Re-Sending: ATZ
--> Modem not responding

Itried run wvdial and kppp with sudo, but invain.
The configs of wvdial and kppp are the same as worked well on Karmic beta.
Could anyone help me, please.
(Sorry my bad English)