Installed Kubuntu 6.06 but I can't get my U.S. Robotics external 56k serial modem to connect. Worked fine with Ubuntu 6.06 and Puppy Linux. Using kppp, would something else work better? Thanks.

Long time since I have done a modem setup, but can you be specific about what you tried so far?

Did you try to set up the modem by going to Start-->Settings-->Networking?

I'm having problems with the latest Kubuntu and a Motorola external serial 56K modem. KPPP from the menu can see the modem and will connect to the internet, but seems to be disconnected from the TCP/IP stack. No internet app will communicate.

From the network manager KPPP acts very differently. It doesn't see the modem at all.

puzzling behaviour
brained

Take a look at the Ubuntu wiki how-to, located here.

Then note the modem section here.

What exact model number is this modem?

The modem is the serial external 56K Motorola VoiceSURFR model 3456 EXT VS US

I found that the network manager is causing all sorts of problems. Exit this and tell it not to load at startup. Just use kppp and all will be well.