This solved a long time frustration I had within PuTTY in that when changing the window size, the terminal columns get all messed up and you get some pretty strange behavior (as seen in this blog post). The solution is to use shopt with the checkwinsize option. This will make sure that your bash terminal will always have the correct number of columns.
shopt -s checkwinsize
After throwing this into my ~/.bashrc file (or ~/.bash_profile, if you prefer), my frustration is gone! Whew!
Check out the man page or this linuxnix.com page for more information.