Pro Search not indexing names with apostrophes

Hi all, I have a site that uses Pro Search for all search on the site. Much of the data is personal names. I have found that search results for data containing names with apostrophes (O’Connor, O’Hanlon etc) result in a list of results were the main records appear, but do not include the name or the additional actual record data. Looking at the Pro Search lexicon the names do not exist, even though they are in the main database, and when I attempt to add these words to the lexicon it says the name is not a valid word.

Any thoughts would be most welcome.