What stupid and not so stupid errors BASH programmers tend to make

On my work I have an ongoing task to rewrite a few bash scripts. Since I always was an admirer of nice & elegant bash scripting and already have some experience in it, I started to dig deeper. What I foung, is this wonderful article by someone, to whom I`m very grateful - Bash Pitfalls. I really wish I could read smth like this a while ago, it saves a lot of time, and shed light on some important aspects of BASH`ing.
Thank you!

For those of you, who`d prefer Russian - here`s and here`s the translation.

Grab yourself an cup of tea\coffee, open vim\emacs and review your own scripts, prehaps you`ll encounter something to remake