Frustration understood. :-)
Where I've seen the problem occur frequently is copy'n'pasting from a web page into an editor or even Thunderbird's entry window, with the offending characters mostly being left and right single and double quotes and an em-dash ("---" as a single horizontal line).
What I (mostly) do now is copy'n'paste from a web page to an Emacs window, and then I can see and correct the bad characters, then copy'n'paste from the Emacs window to Thunderbird's entry windows and everything's fine. Use of Emacs is also great to keep line length around 75 characters or so via ESC-Q after setting the fill column (^U nnn ^X F).
Another choice of editor for Windows users is Textpad, free for personal use and available here:
It's probably *THE* most featureful text editor for a Windows system and yet is extremely easy to use. Among other things it can correct characters and read/save files in Windows and UNIX/Linux formats.
Emacs for Windows is available here (can download with a browser):
and if you want to make the "Caps Lock" a proper [CTRL] key, the best and most reliable and for Win2K, WinXP, Vista and Win7 is here (writeup first):
and, yes, I use it on my Win2K, WinXP, Vista and Win7 systems.
***** Moderator's Note *****Since this post is a big change of subject, I have "de-threaded" it.
I use emacs to edit the Digest, but it's not for the faint-hearted, and I'll warn potential users that there's a big learning curve to climb (Some say the name stands for extend-meta-alt-control-spacebar, due to the way emacs makes extensive use of the Escape, Alt, and control keys). Although emacs offers features - such as "rectangle editing" - which aren't available in most editors, it's a big change from the Windows world.
Other editors may be more user-friendly, but the plain truth is that those whom are used to a what-you-see-is-all-you-get environment will find it easiest to stick with what they know already. The "Official" font of the Digest is "ISO-8859-1", which is a compromise between ASCII and Unicode Transformation Format (UTF): at some point, we'll probably have to convert to UTF-8, but for now I'll just ask readers to not cut and paste unless they _know_ that the result doesn't contain proprietary, non - ISO-8859-1 characters.
Bill Horne Moderator
P.S. There's a wealth of information on this issue, since it's as old as the Internet. Some links I got with a quick search follow: