This problem was solved in my case by changing terminal emulation from VT100 to xterm. Apparently the two programs I was trying don't behave properly when it comes to VT100 terminal line drawing. geekosaur's answer was accepted since it lead me to change what terminal emulation I was using.
I noticed in certain terminal applications, specifically bpython and weechat, that certain characters are not being rendered properly in the terminal are not being rendered. I only just started using these terminal apps again recently after about 1.5 years or so ago back when I was on OSX 10.5 and I don't recall having this problem.
Here are some screenshot examples.
My weechat; notice the ? marks by the nicklist:
What weechat is supposed to look like - a nice thin line separates the nicklist :
My bpython - the border characters are replaced with q's and ?'s:
What bpython is meant to look like:
I've tried messing around with the encoding settings and various fonts, but nothing yet has solved this problem. I'd like to know what the cause of this problem is and how I might go about fixing it.