I just encountered one of those little "quirks" that probably has an easy answer: -
I just did a song with a lyric line that includes an apostrophe - in the word " we're ".  After saving the NWC file as a MIDI file, I changed the file extension from " mid " to " kar ", so that I could open the file with van Basco's Karaoke Player - and I find that " we're " has become " weAEre " (with the AE as a diphthong).  Any ideas please?  Might it be because I am using a UK keyboard?

... To clarify that: The characters are transferred and saved NOT as "characters," but as codes that correspond to characters. Some programs - in particular, MS Word with substitutions enabled (usual situation) - will change the character code automatically. Instead of the code for the single quote you typed, there will be the code for a curly single quote. But this substitute code is not universal. Thus, when the text (that is, the codes for text) is pasted elsewhere, results may differ.

That's not particular to NWC.

Solution: If you use a plain text editor (Notepad), it won't make substitutions.

Thanks guys!
Instead of typing the lyric, I had copied and pasted it from another program.  When I looked carefully, I saw that the pasted version had "curly" apostrophes.  I have now replaced them with straight (typed-in) apostrophes, and it carries through to Van Basco perfectly.

... No, but I'm distantly related to N. Umnutz.