I note that the preview is different than what eventually appears in the post. The preview is fine. The acute character fails.
I included no HTML markup in the test above.
Code
Grave accent (left single quote) - Code 0060: ` Acute accent (right single quote) - Code 00B4: ´ Straight up and down apostrophe - Code 0027: '
Pre Preformatted
Grave accent (left single quote) - Code 0060: ` Acute accent (right single quote) - Code 00B4: ´ Straight up and down apostrophe - Code 0027: '
done