Let's try to go thru this each step of the way to figure this out. We'll start with getting wvdial to work for you and go from there. In both JDS1 and JDS2 this should work( JDS2 won't disconnect for you you though, with modem lights, using this method. I'll explain later how to use gnome-ppp which solves this problem).

1)First let's log in as root, to do that - let's go Launch -applications - system tools - terminal
at terminal prompt, type:
su -
enter root password

then type vim /etc/wvdial.conf (you'll see the file displayed) - you can also do this logged in as root with gedit
touch the i key to insert text, use your arrow key's to navigate down the file (we want to edit baud,phone#,username,passwd) - you will have to use your delete key to edit both baud(115200),and your phone #
when done editing hit the esc key, and type :wq (enter)

2)Now we'll use the chmod commands (you should still be root)

chmod 777 /usr/bin/wvdial (enter)

chmod +s /usr/sbin/pppd (enter)

that should be it for wvdial, it should connect, no problem, to make it a little easier, use modem lights:
right click on panel,
add to panel - internet-modem lights

right click on modem lights icon - preferences
under heading of General

connection command - wvdial

disconnection command - kill wvdial

You should be able to use modem lights now. If you're using JDS2 it won't disconnect. However, using gnome-ppp will solve this problem.

download gnome-ppp http://www.gnome-ppp.org/index.php
once downloaded you going to have to make it (it's a .tar file) to do this, we'll do:

1) go to folder that you saved the download

2) right click on file - open with file roller, extract to your home directory, it should create a folder.

3)Launch - applications - system tools - terminal

4) type:

cd /home/gw(or whatever)/gnome-ppp(whatever the folder created is)
type:
./configure (it'll take a minute or two)
type:

make (it will take longer - grab a coffee)
when that's done, we need to change to root, to do this type:

su -
enter root password
type:

cd /home/gw(whatever)/gnome-ppp(whatever the folder created is)
type:

make install

exit the terminal you're now done

5)go to launch - run application, type: gnome-ppp

edit your properties, add username,password,phone#
6)Test your connection

That's it, you should have no problem, connecting and disconnecting from the internet. You can add gnome-ppp to your panel, just right click on panel and add launcher. the command is /usr/local/bin/gnome-ppp