Please try the following and let us know which works:
It may take some troubleshooting but we should be able to figure this out
- Check your character encoding settings (what is your setting?)
- Turn off automatic/smart quotes
- Are you replying back and forth with someone from another country?
- What language is your computer set to? Are you on a Windows PC?
- Make sure your anti-virus software is up to date too
Smart Quotes can be disabled in the registry:
- how do I turn off smart quotes?