A few Arch-related issues (tmux, screen, urxvt)

Hey everyone. Everything's been going quite smoothly with my two Arch-based Linodes lately, aside from a couple of minor issues.

I use rxvt-unicode as the terminal on the computers I access the servers from and on one of them I have GNU Screen installed. I can attach and detach from Screen all right, but upon detaching the contents of what were displayed in Screen are not cleared. The cursor moves to the right place, but instead of returning to a blank(ish) prompt, I'm left with text over text. Here is an example of what it looks like:

~~http://oi51.tinypic.com/fmnqmf.jpg" />

This only happens with rxvt-unicode and I don't understand why. It may be a change in the software that has led to it, but it seems to only happen when I access these two servers.

My second issue is with tmux, which I use on the other server. Or at least, that was the plan. On previous Linodes that I've had, tmux would work without issue, but now after installation I cannot get it to work. I execute the tmux command, the terminal flickers and then I am left sat still at the prompt. My home computer runs Arch Linux and is as up-to-date as the Linode server, but I can run tmux just fine on this whether it is locally or over SSH.

Would anybody have any ideas as to why this might be happening or at least some tips on tracking down the cause(s)?

Regards,

Joel.~~