I suspect the confusion around single quotes and double-quotes is triggered by "regular expressions" in the JavaScript logic that are checking for possible security threats that can stem from hackers injecting malicious code by "escaping" it via character sequences. The logic handling post submission runs your message text through these regular expressions to disable any sequences that might result in SQL injections, etc. when the form submits your post to the web server.

I noticed something else on these shrewdm boards a while back in a simliar vein after simplifying HTML from a blog post to be compatible with the formatting allowed here but now can't remember what it was.

The new boards on TMF have some weird issues as well. If you try to use a line of equals signs to highlight a block of text, something in TMF's new formatting converts it to an HTML bold tag. Typing this

==================
This
That
Those
==================

This is regular text again.

results in the first equals line and the three items being bold, no closing equals line then regular text for "This is regular text again."

WTH