This answer of mine has some italicized words containing underscores in the first line. These look good in the preview, but in the answer they appear non-italicized with surrounding asterisks.
Is this a known bug, and is there a workaround?
Workaround - write the italics tag yourself. For example:
Use attr_accessor to add attributes
Ugly, but it works.
As for whether it's a known bug - it's known now ;) (Things like this are fundamentally tricky for markdown, unfortunately.)
The server-side markdown parser does not like mixing _ and *.
Don't cross the streams!