[dblitt]

IIRC TextEdit.app has options like smart quotes, auto capitalize, and spell check turned on (in addition to being rich text by default), so you have to change all those to be a dumb plain text editor.

[fishyjoe]

TextEdit and the Notes app have both caused me to copy/paste the specialized quotation marks.

Now I only use vim as a scratchpad because I've been bitten too much by GUI apps