When going back and adding BOLD or italics to a word in a message that you've just written, that act seems to delete the space between the word you've bolded or italicized and the word following it.

I was writing becomes I was writing...

or

I was writing becomes I was writing...

It did NOT happen when I wrote the above here.  I even went back and edited the message, rewriting the text to see if it only happens when editing.  I also tried it with and without leaving theword highlighted when submitting it.  Apparently it doesn't happen all the time, but it's now happened enough that it caught my eye enough times to mention it.