This is not an issue that I"m able to reproduce with the sample you posted. It does not seem to be adding in the extra apostrophes for me. Have you made any edits to any of the HTML Editor instances on any of these pages in the admin area?
When you insert new content that has the apostrophe in it do you see it doubled up in the preview of the content immediately after inserting it? If you could post back and include copies of your contents update and contents insert pages I can look to see if I can spot any issue with the code on this page that would cause this.