Serial modem output interference on linux command line

I am manually dialing remote machines using my serial modem via the linux command line. I am automating the process, hence not using any dialing tools (I've already tried most of them - none are sufficient).

I can make connections successfully - however when I turn on the verbose option on my modem ("AT V1"), the output and input of my device seems to be interspersed with excessive newlines. I'm sending commands to my modem with "echo 'command' > /dev/ttyS0", then listening on another terminal with "cat /dev/ttyS0". The newlines steadily increase in number, and are also sent to the serial connection, making it impossible to enter a username or password, or any other data. Eventually the connection is terminated due to multiple failed login attempts.

I captured the entire sequence as an example and pasted it here: http://pastebin.com/j8Fc236m

From serverfault tjbp

• Check "man stty" and investigate various character conversion settings.

  Dennis Williamson : Please add the particular configuration change that fixed this problem. It may be useful to someone who comes along later and has a similar problem.
  From tjbp