Using OS X 10.6 I see the same thing from the Terminal.app program when I connect to both of my Ubuntu 9.10 servers.
I checked the preferences of the terminal app and under advanced; the setting "Delare Terminal As:" was set to XTERM (not sure if that is the default or if I changed it to that). I changed the setting to declare the terminal as xterm-color and that fixed the issue for me.
Using OS X 10.6 I see the same thing from the Terminal.app program when I connect to both of my Ubuntu 9.10 servers.
I checked the preferences of the terminal app and under advanced; the setting "Delare Terminal As:" was set to XTERM (not sure if that is the default or if I changed it to that). I changed the setting to declare the terminal as xterm-color and that fixed the issue for me.